Concept:Lexical words, also called content words, carry the main meaning in a sentence. They include nouns, verbs, adjectives, and most adverbs.
Explanation:Lexical words are meaningful and give information about things, actions, or qualities. For example, “bird,” “fear,” and “book” are lexical words.
The word “principal” is a noun that names a person or a thing, so it is a lexical word.
Other options are function words: “some” is a determiner, “whether” and “if” are conjunctions. Function words help grammar but do not carry the main meaning.
Therefore, only “principal” is a lexical word.
Answer:Principal (Option C)