How does mistake, if proved, affect third parties $($persons outside of the contract in which the mistake occurred$)?$

Question $10$Answer

a$.$

If mistake is proved, there is no effect on third parties.

b$.$

If mistake is proved, the contact is voidable and third parties are affected only if the they knew of the mistake.

c$.$

If mistake is proved, the contract is unenforceable as against third parties.

d$.$

If mistake is proved, the contract is illegal and therefore unenforceable against third parties.

e$.$

If mistake is proved, the contract is void and third parties who claim benefits from the void contract will be adversely affected.