First National Bank Signs an Agreement Not to Compete with City

First National Bank signs an agreement not to compete with City Bank that will bar City Bank from continuing to operate in the state in which both banks do almost all of their business.The agreement is likely

A) an unreasonable restraint of trade.
B) enforceable.
C) enforceable if it is ancillary to an agreement by the First National Bank to purchase all of the assets of the City Bank.
D) none of the choices.