Read the following excerpt from a US court opinion:
```
to do so may result in a reprimand, a suspension of their license, or a permanent revocation of their license. See Cornell v. Wunschel, 408 N.W.2d 369, 377 (Iowa 1987) (stating that “the code of professional responsibility sets the standard for an attorney’s conduct in any transaction in which his professional judgment may be exercised”); Iowa Sup.Ct. R. 118.10 (discussing discipline by supreme court). It is also significant that the underlying goal of the licensing and supervision of attorneys is to protect the public from the consequences of unqualified legal advisors. See Comm. on Prof'l Ethics & Conduct v. Lawler, 342 N.W.2d 486, 488 (Iowa 1984). These facts unquestionably demonstrate that the attorney licensing requirement has a regulatory purpose. Cf. Mincks, 611 N.W.2d at 277 . We now determine whether “the interest in the
```
What is the most suitable continuation to the opinion? Your options are:
A. holding that grain dealer licensing statute has a regulatory purpose where the department of agriculture and land stewardship has general supervision over grain dealers and the purpose behind the statutory licensing requirement is protection of the public
B. recognizing that the primary purpose of tr  162051 is protection of the public
C. holding that the prohibitions under the statute do not prevent a manufacturer from terminating a contract with a dealer where the dealer has over a long period of time violated a valid and material clause of the contract and has failed to comply with the continuing insistence of the manufacturer upon performance
D. recognizing frustration of purpose where an unexpected regulatory change substantially frustrated the principal purpose of the agreement to the unfair advantage of one party
E. holding that a defendant is in custody and miranda applies even when the purpose of defendants detention is unrelated to the purpose of the interrogation
Reply with [A, B, C, D, E] only.