Answer:
b. The consideration, although disproportionate, is nevertheless adequate because he was done freely
Explanation:
Consideration is one of the essential elements of a valid contract, it is the quid pro quo of a contract, that is, something for something. Consideration is anything of value exchanged for services rendered, goods supplied, or promise. it is the value of what parties to a contract get in a contractual deal.
It must be noted that in the eyes of the law consideration need not be adequate but must be sufficient for the contract.