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

<passage>:
Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] They didn't realize they were in trouble until it was too late to stop ship from HQ in Standard GPP Contract code for crash priority, which meant Top Grade Planetary Emergency, and don't argue about it, fellows, bodily. The last time an Earth ship landed there half the crew was the folks on Morua II didn't want a Contract with Hospital Earth. And they couldn't possibly know." The surgeon in the green undershorts chewed his lip. "Looks like crash-priority call, regardless of circumstances—" Contract had been signed with Deneb III centuries before, Hospital Earth had laboriously built its reputation on that single foundation stone: immediate medical assistance, without question or hesitation, whenever and wherever it was required, on any planet bound by Contract. That was the law, for Hospital Earth could not afford to jeopardize a Contract. In the early days of galactic exploration, of course, Medical Services but in any growing civilization division of labor inevitably occurs. Other planets outstripped Earth in technology, in communications, in transport, and in production techniques—but Earth stood unrivaled in its development of the biological sciences. Wherever an Earth ship landed, the crew was soon rendering Medical Services of one sort or the Medical Service Contract was formalized, and Hospital Earth came they came across. Serious problems were shuttled back to Hospital Earth without delay more frequently the GPP crews—doctors of the Red and Green services, representing the ancient Earthly arts of medicine and surgery—were able to handle the problems on the spot and by themselves. It was a rugged service for a single planet to provide, and it was costly. Many planets studied the terms of Contract and declined, "You're lucky we came at all," he said peevishly. "Where's your Contract? Where did you get the Code?" "Bother the Contract," the Moruan snarled. "You're supposed to be physicians, eh?" He eyed them up and down as though he disapproved of everything that he saw. "You make sick people well?" illness is this?" he whispered. "He is afflicted with a Pox, as any fool can see. All others it does not die. We have you here now. You are doctors, you say. Cure "How should I know? I've never seen a healthy Moruan before, to say nothing of a sick one. It looks like a pox all right." new ones—" Jenkins turned to Aguar. "How long has this gone on?" "For days," the Moruan growled. "He can't speak. He grows hot and cannot eat. He moans until the Palace trembles." "What about your own doctors?" Aguar spat angrily on the floor. "They are jealous as cats until trouble comes. Then they hide in the caves like chickens. See the "We'll need supplies and information from our ship. We'll have to consult your physicians. We'll need healthy Moruans to examine—" "But you will cure him," Aguar said. he didn't die naturally we'd kill him for sure! We can't go near him without a Bio-survey—look what happened on Baron when they tried it! Half the planetary population wiped out before they realized that the antibiotic was more deadly to the race than the virus was...." "Might not be such a bad idea for Morua," the Red Doctor muttered grimly. "Well, what did you expect me to do—politely refuse? And "Well, we've got a little to go on just from looking at them. They're oxygen-breathers, which means they manage internal combustion of carbohydrates, somehow. From the grey skin color I'd guess at a cuprous or stannous heme-protein carrying system. They're carnivores, but god knows what their protein metabolism is like—Let's get going on some of these specimens Aguar has rounded up for us." They dug in frantically. Under normal conditions a GPP ship would send in a full crew of technicians to a newly-Contracted planet to make the initial Bio-survey of the indigenous races. Bio-chemists, physiologists, anatomists, microbiologists, radiologists—survey workers from every Service would examine and study the new clients, take them apart cell by cell to see what made them tick. Certain basic principles were always the same, a fact which accelerated the program considerably. Humanoid or not, all forms of life had basic qualities in common. Biochemical reactions were biochemical reactions, a jelly-blob, and would never rise above the level of amoeboid yes-no response because of its utter lack of organization. But a creature with an organized central nervous system and a functional division of work among organ systems could be categorized, tested, studied, and compared, and the information used in combating native disease. Given no major setbacks, and full cooperation of the natives, the job only took about six months to do— handled external examinations and blood and tissue chemistries Stone ran the X-ray and pan-endoscopic examinations. After four grueling hours the Red Doctor groaned and scowled at the growing pile of data. "Okay. It seems that they're vaguely humanoid. And that's about all we can say for sure. I think we're wasting time. What say we tackle the Wizards for a while?" it run?" Silence. "All right then, what causes it? Do you know? Bacteria? Virus? Degeneration?" Silence. Jenkins' face was pale. "Look, boys—your Boss out there is going to violently on the idea of a Hospital Earth Contract, eh? Couldn't risk "The Spirit of the Pox is too strong. Our most powerful spells make him laugh. He eats our powders and drinks our potions. Even the Iron Circle won't drive him out." "Won't it, now! Well, we have iron needles and potions that eat the promises, pills and post-mortems. That's the Medical service for you." That would open their "No thanks, not me. This is a medical case and it's all yours. What do poke holes in the healthy ones! And then you send in this bag of ever recover from this?" "Oh, yes—if the Spirit that afflicts them is very small. Those are the fortunate ones. They grow hot and sick, but they still can eat and drink—" The wizard broke off to stare at the bottle-and-tube arrangement Jenkins had prepared. "What's that?" down on a bench in the hall and fell asleep in an instant. They woke him once, hours later, to change the intravenous solution, Morua is not a Contract planet and we're not supposed to be here in the Services of Hospital Earth. "Take a look, my boy—the juiciest Medical finished his first lesson, and he's still wondering what went on—" "So am I," said the Green Doctor suspiciously. "With what? Incantations?" "Oh, the incantations were for the doctors ," said Jenkins. "They expected them, obviously, since that was the only level of medicine they could understand. And incidentally, the only level that could possibly get us a Contract. Anyway, I couldn't do very much else, under involves fever, starvation and dehydration. I knew that His Eminence could assimilate carbohydrates, and I took a long gamble that an antipyretic wouldn't hurt him too much—" one other prescription to use—the oldest, most trustworthy healer-of-all-ills known to medicine, just as potent now as it was a thousand years ago. Without it, Hospital Earth might just as well pack

<question>:
Why is it risky for a planet to receive services when they are not under contract with Hospital Earth?

<options>:
A Hospital Earth may come to collect collateral for their services, which has been known to start war
B The physicians are known to be brutal and sometimes kill patients from planets that aren’t under contract
C The cost may be extremely expensive for emergency services outside of the contract, taking centuries to repay
D Their biology is not understood well, and mistakes can be made

<answer>:

D