In the context of phonology what is the term for the smallest unit of sound that can change the meaning of a word

In the context of phonology, what is the term for the smallest unit of sound that can change the meaning of a word?

A. Phoneme
B. Syllable
C. Morpheme
D. Allophone

A phoneme is the smallest unit of sound that can change the meaning of a word.

Phonetics and Phonology Question Details