Question

last year i wasnt on my a-game but this year is going to be my best year. i wanna be able to stay on task for every class, to not get mad at anything somebody says to me, and i wanna learn how to survive in social environments. happy new years. -- nas
the expression a-game is an example of...
idiom
alliteration
simile
personification

Explanation:

An idiom is a common phrase with a non - literal meaning. "A - game" means one's best effort or performance, and its meaning is not deducible from the literal meanings of "A" and "game". Alliteration is the repetition of initial consonant sounds, simile uses "like" or "as" to make comparisons, and personification gives human traits to non - human things. None of these other literary devices apply to "A - game" as it does to an idiom.

Answer:

A. idiom