Concept:The part of speech of a word depends on how it is used in the sentence.
Explanation:In the sentence "Turn right at the end of the street", the word "right" gives the direction of the action "turn".
It modifies the verb "turn" by answering the question "in which direction?".
A word that modifies a verb, an adjective, or another adverb is called an adverb.
Here, "right" is not describing a noun, so it is not an adjective.
It is not naming a person, place, thing, or idea, so it is not a noun.
It is not showing a relationship like "at" or "in", so it is not a preposition.
Therefore, in this sentence, "right" functions as an adverb.
Answer:B. Adverb