A, because to eat describes what she will do with the apple, and adjectives describe nouns (apple is a noun).
The abbreviation that's shown after a word in the dictionary tells you what part of speech the defined word is.
The word could be defined as a:
noun (n)
pronoun (pron)
adjective (adj)
adverb (adv)
verb (vb)
conjunction (conj)
preposition (prep)
interjection (interj)
I think it would be the word of heavy traffic.
