Final answer:
The syntactic category of a word determined by affixes is called morphology, not transformation which relates to cellular DNA uptake. The correct answer to the question is b.
Step-by-step explanation:
We can determine the syntactic category of a word by the affixes attached to it, which is also called morphology. The correct answer to the question is b. Morphology. Morphology involves studying the structure and form of words in a language, including the way words are formed through the use of affixes (prefixes, suffixes). This differentiates it from derivation, which refers to the creation of new words by adding affixes, and inflection, which pertains to the modification of words to express different grammatical categories such as tense, mood, voice, aspect, person, number, gender, and case. The option transformation, as provided in the context, is incorrect here, since it relates to the process of uptake of external DNA by a cell.