Which of the following statements about mutual mistake of a basic assumption is true?

A. The parties must be consciously aware of the assumption.

B. An assumption is basic even when it concerns a matter that bears an indirect or collateral relationship to the subject matter of the contract.

C. Assumptions about the identity, existence, quality, or quantity of the subject matter of the contract are considered to be basic assumptions.

D. A contract can be avoided even if the mutual mistake was not based on a basic assumption.