In order to convert a proposal into a promise, the acceptance must be:

Correct option is D

As per Section 7(1) of the Indian Contract Act, 1872, for a proposal to be converted into a promise, the acceptance must be absolute and unqualified. A conditional acceptance does not create a valid contract.
Information Booster:
· Both "absolute" and "unqualified" are essential traits of a valid acceptance, but among the given options, only (b) unqualified captures the legal precision required under the Act.
· Option (a) is close, but the law emphasizes "unqualified" to rule out counter-offers or conditions.