Topic: Adjective (বিশেষণ),

Best Answer Explained in Below-:

In the line "'Fair' Daffodils, we weep to see," the underlined word "fair" functions as an adjective. Adjectives are words that describe or modify nouns, providing more information about them. In this context, "fair" describes the noun "Daffodils," suggesting they possess a quality of beauty, lightness, or attractiveness.

Understanding the word "fair" in this context is crucial; it conveys a sense of admiration or longing, emphasizing the speaker's emotional response to the daffodils' beauty. The use of “fair” instead of another descriptive term indicates not just appearance but also an idealized perception, often linked to themes of nature and fleeting beauty.

While "fair" could theoretically take on other grammatical roles in different contexts, here it is clearly serving as an adjective based on its placement before the noun "Daffodils" and its function in enhancing the meaning of that noun. Thus, option C, "adjective," is the correct choice because it accurately identifies the grammatical role of "fair" in this phrase.