Explanation:

Adjective:
An adjective is a part of speech that describes or modifies a noun. It adds something to the meaning of a noun by providing more information about it. Adjectives can describe the size, color, shape, quality, or other characteristics of a noun. For example, in the sentence "The tall tree swayed in the wind," the adjective "tall" adds information about the size of the tree.

Other Options:
Let's briefly discuss the other options given in the question and why they are not the correct answer.

a) Pronoun:
A pronoun is a word that is used in place of a noun. It can refer to a person, thing, place, or idea. Pronouns are used to avoid repetition and to make sentences less repetitive. They do not add something to the meaning of a noun; instead, they replace nouns. For example, instead of saying "John went to the store," we can say "He went to the store" using the pronoun "he" to refer to John.

b) Adverb:
An adverb is a part of speech that modifies a verb, adjective, or other adverb. It adds information about how, when, where, or to what extent an action is performed. Adverbs do not directly add something to the meaning of a noun. For example, in the sentence "She ran quickly," the adverb "quickly" describes how she ran.

d) Interjection:
An interjection is a part of speech that expresses strong emotions or sudden bursts of feeling. Interjections are usually standalone words or phrases and do not directly add something to the meaning of a noun. They are used to convey emotions such as surprise, joy, or frustration. For example, "Wow! That's amazing!" or "Ouch! That hurt!"

Conclusion:
The correct answer is option C, adjective. Adjectives add something to the meaning of a noun by providing additional information about it. They describe or modify nouns and can specify their size, color, shape, quality, or other characteristics.

Pronoun