What is the definition of Alliteration?

A. The occurrence of the same letter or sound at the beginning of adjacent or closely connected words

B. The formation of a word from a sound associated with what is named (e.g. cuckoo, sizzle, boom, pop)

C. Spongy, cushioned feeling when walking on a flexible surface

D. Writing that is based on facts, real events, and real people, such as biography or history