What are,if any,the possible defenses against a valid contract which may cause it to be unenforceable?

Question

Quizplus · Accepted Answer

The genuineness of assent and form of the contract can render it unenforceable if there was misrepresentation, mistake, undue influence, or duress involved in the formation of the agreement. Additionally, if the contract lacks proper form, such as not being in writing or lacking formalities required by law, it may also be unenforceable.

B, C, and D are all necessary elements for a valid contract and are not defenses against enforceability.

What Are,if Any,the Possible Defenses Against a Valid Contract Which