Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
Krugman's Life of Brian Where it all started: Paul Krugman's                 "The Legend of Arthur." Letter from John Cassidy Paul Krugman replies to John Cassidy Letter from M. Mitchell Waldrop Paul Krugman replies to M. Mitchell Waldrop Letter from Kenneth J. Arrow Letter from Ted C. Fishman David Warsh's July 3, 1994, Boston Globe Letter from John Cassidy: Paul Krugman loves to berate journalists for their ignorance of economics, particularly his economics, but on this occasion, I fear, his logic is more addled than usual. I am reluctant to dignify his hatchet job with a lengthy reply, but some of his claims are so defamatory that they should be addressed, if only for the record. 1) Krugman claims that my opening sentence--"In a way, Bill Gates's current troubles with the Justice Department grew out of an economics seminar that took place thirteen years ago, at Harvard's John F. Kennedy School of Government"--is "pure fiction." Perhaps so, but in that case somebody should tell this to Joel Klein, the assistant attorney general in charge of the antitrust division. When I interviewed Klein for my piece about the Microsoft case, he singled out Brian Arthur as the economist who has most influenced his thinking about the way in which high-technology markets operate. It was Klein's words, not those of Arthur, that prompted me to use Arthur in the lead of the story. 2) Krugman wrote: "Cassidy's article tells the story of how Stanford Professor Brian Arthur came up with the idea of increasing returns." I wrote no such thing, and Arthur has never, to my knowledge, claimed any such thing. The notion of increasing returns has been around since Adam Smith, and it was written about at length by Alfred Marshall in 1890. What I did say in my article was that increasing returns was largely ignored by mainstream economists for much of the postwar era, a claim that simply isn't controversial. (As Krugman notes, one reason for this was technical, not ideological. Allowing for the possibility of increasing returns tends to rob economic models of two properties that economists cherish: simplicity and determinism. As long ago as 1939, Sir John Hicks, one of the founders of modern economics, noted that increasing returns, if tolerated, could lead to the "wreckage" of a large part of economic theory.) 3) Pace Krugman, I also did not claim that Arthur bears principal responsibility for the rediscovery of increasing returns by economists in the 1970s and 1980s. As Krugman notes, several scholars (himself included) who were working in the fields of game theory and international trade published articles incorporating increasing returns before Arthur did. My claim was simply that Arthur applied increasing returns to high-technology markets, and that his work influenced how other economists and government officials think about these markets. Krugman apart, virtually every economist I have spoken to, including Daniel Rubinfeld, a former Berkeley professor who is now the chief economist at the Justice Department's antitrust division, told me this was the case. (Rubinfeld also mentioned several other economists who did influential work, and I cited three of them in the article.) --John Cassidy Paul Krugman replies to John Cassidy: I think that David Warsh's 1994 in the Boston                 Globe says it all. If other journalists would do as much homework as he did, I wouldn't have had to write that article. Letter from M. Mitchell Waldrop: I leave it for others to decide whether I was too gullible in writing Complexity . For the record, however, I would like to inject a few facts into Krugman's story, which he summarizes nicely in the final paragraph: When Waldrop's book came out, I wrote him as politely as I could, asking exactly how he had managed to come up with his version of events. He did, to his credit, write back. He explained that while he had become aware of some other people working on increasing returns, trying to put them in would have pulled his story line out of shape. ... So what we really learn from the legend of Arthur is that some journalists like a good story too much to find out whether it is really true. Now, I will admit to many sins, not the least of them being a profound ignorance of graduate-level economics c) So, when I received Krugman's letter shortly after Complexity came out, I was puzzled: He was complaining that I hadn't referenced others in the increasing-returns field--Paul Krugman among them--although I had explicitly done so. d) But, when I checked the published text, I was chagrined to discover that the critical passage mentioning Krugman wasn't there. e) Only then did I realize what had happened. After I had submitted the manuscript, my editor at Simon &amp --M. Mitchell Waldrop Washington Paul Krugman replies to M. Mitchell Waldrop: Paul Krugman's attack on Brian Arthur ("The Legend of Arthur") requires a correction of its misrepresentations of fact. Arthur is a reputable and significant scholar whose work is indeed having influence in the field of industrial organization and in particular public policy toward antitrust policy in high-tech industries. Krugman admits that he wrote the article because he was "just pissed off," not a very good state for a judicious statement of facts, as his column shows. His theme is stated in his first paragraph: "Cassidy's article [in The New Yorker of Jan. 12] tells the story of how Stanford Professor Brian Arthur came up with the idea of increasing returns." Cassidy, however, said nothing of the sort. The concept of increasing returns is indeed very old, and Cassidy at no point attributed that idea to Arthur. Indeed, the phrase "increasing returns" appears just once in Cassidy's article and then merely to say that Arthur had used the term while others refer to network externalities. Further, Arthur has never made any such preposterous claim at any other time. On the contrary, his papers have fully cited the history of the field and made references to the previous papers, including those of Paul Krugman. (See Arthur's papers collected in the volume Increasing Returns and Path Dependence in the Economy, especially his preface and my foreword for longer comments on Arthur's work in historic perspective. Click to see the foreword.) Hence, Krugman's whole attack is directed at a statement made neither by Arthur nor by Cassidy. Krugman has not read Cassidy's piece with any care nor has he bothered to review what Arthur has in fact said. --Kenneth J. Arrow Nobel laureate and Joan Kenney professor of economics emeritus Stanford University Letter from Ted C. Fishman: After reading Paul Krugman vent his spleen against fellow economist Brian Arthur in "The Legend of Arthur," I couldn't help wondering whose reputation he was out to trash, Arthur's or his own. Krugman seems to fear a plot to deny economists their intellectual due. If one exists, Arthur is not a likely suspect. In a series of long interviews with me a year ago (for Worth magazine), I tried, vainly, to get Arthur to tell me how his ideas about increasing returns have encouraged a new strain of economic investigations. Despite much prodding, Arthur obliged only by placing himself in a long line of theorists dating back to Adam Smith and Alfred Marshall. I also found him disarmingly generous in giving credit to the biologists, physicists, and fellow economists who have helped advance his own thinking. Savvy to the journalist's quest for heroes, Arthur urged me to focus on his ideas, not his rank among his peers. Krugman has made a career out of telling other economists to pay better attention to the facts, yet as a chronicler of Arthur's career and inner life, Krugman seems to have listened only to his own demons. --Ted C. Fishman (For additional background on the history of "increasing returns" and Brian Arthur's standing in the field, click for David Warsh's July 3, 1994,                                 Boston Globe                                    article on Brian Arthur)

<question>:
Who does John Cassidy refer to as the “Santa Fe professor”?

<options>:
A Joel Klein
B Brian Arthur
C Daniel Rubinfeld
D Paul Krugman

<answer>:

B