Final answer:
A morpheme is the smallest unit of language that conveys meaning, such as 'I'. Phonemes are basic sound units, but do not convey meaning on their own. Therefore, the answer is B. morpheme.
Step-by-step explanation:
A phoneme is a basic sound unit of a language that differentiates meaning (e.g., 'ah' vs. 'eh'). However, a morpheme is the smallest unit of language that conveys some type of meaning, such as the word 'I', which is both a phoneme and a morpheme. When phonemes are combined, they form morphemes. Hence, semantics and syntax use morphemes and words to construct meaningful language.
The correct answer to the question 'A ________ is the smallest unit of language that conveys some type of meaning.' is B. morpheme.