Option B is the correct option. "Loud" is an adjective. Adjectives are a part of the parts of speech. An adjective is a word that is used to add something to the meaning of the noun or pronoun. Adjectives add quality, quantity, number, demonstration, etc., to the noun or pronoun. It states the being of a noun or pronoun. They can describe or modify the meaning of the noun or pronoun. E.g. She has a charming (quality) personality; My mother bought three (quantity) apples from the market; Reena brought some (number of nouns/pronouns) books from the library.