______ is the smallest unit of sound.

• A. Phonology
• B. Morpheme
• C. Phoneme
• D. Allophone

Answer: (C)

The smallest unit of sound that can distinguish meaning is a phoneme. A phoneme is an abstract category that helps us tell words apart; the actual sounds we hear are concrete realizations called phones, and the same phoneme can be realized as different allophones depending on context without changing meaning. For example, the sounds that occur at the beginning of “pat” and “bat” contrast to signal different words, illustrating how phonemes create meaning distinctions. The sounds in “pin” and “spin” may be different in pronunciation (an aspirated vs. unaspirated version) but often belong to the same phoneme in many dialects, so they don’t create new words. Morpheme, by contrast, is about meaning, not sound. Phonology is the study of sound systems and patterns, not a single unit of sound. Allophones are variants of a phoneme, not separate units that change meaning.