Step 1: Understand the different types of contracts.
A void contract is not enforceable by law. It is invalid from the beginning or becomes invalid due to some reason.
A valid contract is enforceable by law and is binding on all parties.
An enforceable contract generally refers to a valid contract that meets all legal requirements and is legally binding.
A voidable contract is a valid contract but gives one party the option to either enforce or cancel it.
Step 2: Focus on the phrase "enforceable by law at the option of one party."
This clearly describes a situation where one party has the power to enforce the agreement, while the other party is bound.
Example:
If a contract is made under coercion, the party who was coerced can either:
continue with the contract (enforce it), or
cancel it (make it void).
This makes the contract voidable at the option of the coerced party.
Conclusion:
Hence, the correct type of contract that fits this definition is a voidable contract.