Which of the Following Must a Mutual Mistake Involve in Order

Which of the following must a mutual mistake involve in order for a mutual mistake to interfere with legal consent?

A) A basic assumption about the subject matter of the contract.
B) A material effect on the agreement.
C) A basic assumption about the subject matter of the contract and an adverse effect on a party who did not agree to bear the risk of mistake at the time of the agreement, but not a material effect on the agreement.
D) A basic assumption about the subject matter of the contract, an adverse effect on a party who did not agree to bear the risk of mistake at the time of the agreement, and a material effect on the agreement.
E) An admission by one of the parties that a misrepresentation occurred.