Rescission of contracts may be allowed if:

Answer: Option A

Rescission of contracts refers to the cancellation of a contract, returning the parties to the positions they were in before the contract was made.

Rescission may be allowed if:

Where the contract is voidable at the instance of the plaintiff: This means that if the contract can be voided by the plaintiff, rescission can be sought. This typically happens in cases of misrepresentation, fraud, undue influence, or mistake.

Option B: When the contract is void, rescission is generally not required because a void contract is already considered legally unenforceable.

Option C: If a third party acquires an interest in the contract in good faith, rescission may not be allowed to protect the third party's rights.

Therefore, the correct answer is Option A: Where the contract is voidable at the instance of the plaintiff.