Topic: Interjection,

Best Answer Explained in Below-:

The phrase "word of buts is a--" implies that the term "buts" serves as a noun in the context of the sentence. To understand this, we can break down the sentence structure and the function of words within it.

Firstly, nouns are words that represent a person, place, thing, or idea. In this case, "buts" represents an idea—specifically, it indicates objections, conditions, or reservations, typically introduced in arguments or discussions. Therefore, it functions as a noun because it is the subject of the phrase "word of buts."

Referring to the options provided:

- **A) Conjunction**: This category includes words that connect clauses or sentences, such as "and," "but," and "or." While "but" itself is a conjunction, "buts" in the given context is not functioning in this way.

- **B) Preposition**: Prepositions describe relationships between nouns or pronouns and other concepts, such as "in," "on," or "with." "Buts" does not fit this role.

- **C) Noun**: As stated, "buts" represents a concept or idea, making it a noun.

- **D) Pronoun**: Pronouns replace nouns but “buts” does not serve this purpose.

Thus, in this context, the correct classification for "buts" is indeed **C) Noun**.