Topic: Adverb (ক্রিয়াবিশেষণ),

Best Answer Explained in Below-:

An adverb is a word that modifies a verb, an adjective, or another adverb, often providing information about how, when, where, or to what extent an action is performed. In the given options, the word "shyly" (B) is the only adverb. It describes the manner in which an action is performed, indicating that something is done in a shy way. For example, in the sentence "She spoke shyly," the adverb "shyly" modifies the verb "spoke," clarifying how she spoke.

The other options—"brave" (A), "beautiful" (C), and "bold" (D)—are adjectives. Adjectives describe nouns, providing more information about their qualities. "Brave" describes a person who is courageous, "beautiful" refers to someone or something that is visually appealing, and "bold" suggests audacity or confidence. While they add depth to descriptions, they do not modify verbs or actions and therefore do not fit the definition of an adverb. Thus, "shyly" is the correct answer, as it distinctly functions as an adverb in language.