Sam and Martha Sign a Contract in Which Sam Agrees

Multiple Choice

Sam and Martha sign a contract in which Sam agrees to pay a certain price and buy Martha's house. Later, Sam's brother states that Sam often has intervals of delusions and hence the contract is invalid because it has been made by an incompetent person. Sam has not been declared by the court as insane. In such a scenario, according to law, which of the following will entitle Martha to the price agreed upon in the contract?

A) Martha was not aware of Sam's mental condition while signing the contract.
B) Martha will incur a huge loss if the contract is held invalid.
C) Sam was in a sane frame of mind and understood the contract when he signed it.
D) Sam signed the contract on his own and was not forced to do so.