Blueberry Café Signs an Agreement with County Credit Bank to Borrow

Blueberry Café signs an agreement with County Credit Bank to borrow $40,000 at 20 percent interest.Later,the state legislature passes a law lowering the maximum permissible rate of interest to 15 per?cent.Blueberry's best argument for avoiding payment to County Credit is that

A) performance of the contract is commercially impracticable.
B) payment of the loan would force the debtor into bankruptcy.
C) the law has rendered performance of the contract illegal.
D) the specific subject matter of the contract has been destroyed.