The definition of a word comprises the following points EXCEPT（

The definition of a word comprises the following points EXCEPT（ ）.
A、a sound unity
B、a unit of meaning
C、the smallest form of a language
D、a form that can function alone in a sentence
【正确答案】：C
【题目解析】：从结构上讲，词并不是最小的单位，词素（morpheme）才是。