The correct option is D Litotes
Option D is the correct answer. Litotes, derived from a Greek word meaning “simple,” is a figure of speech that employs an understatement by using double negatives ("not unfamiliar") or, in other words, a positive statement expressed by negating its opposite expressions. The other options are wrong as metonymy, alliteration, and synecdoche mean a representative word which stands for something else, a series of words use the same consonant and a word which is a term for a part of something but refers to the whole of itrespectively. The correct answer is D) Litotes.