Topic: Adverb (ক্রিয়াবিশেষণ),

Best Answer Explained in Below-:

In the sentence "He doesn't like Beethoven and neither do I," the word "neither" functions as an adverb. It is used to express agreement with a negative statement, indicating that the speaker shares the same disfavor for Beethoven as the person previously mentioned.

Adverbs modify verbs, adjectives, or other adverbs and often provide information about the manner, degree, or negation of an action. In this context, "neither" negates the liking of Beethoven, applying to the verb phrase "do I" in the second clause. Essentially, it reinforces the negation introduced by "doesn't like?" It can be understood as a shorthand way of saying, "I also do not like Beethoven."

It's important to note that "neither" can sometimes be considered in other grammatical contexts, but in this specific example, it operates within the structure of the sentence to align the speaker with the negative sentiment expressed by another person. Thus, the correct answer is B) Adverb.