Read the sentence. As the boy sneaked down the hallway, he came upon a door that was ajar, which he could just barely peek through to see the splendid artifacts displayed in their carefully locked cases.

The definition of ajar is “slightly open.”

Which context clue confirms this meaning?

A. Ajar is a synonym of door.

B. Ajar is an adverb describing the boy.

C. Ajar is an adjective describing the door.

D. Ajar is a noun referring to the artifacts.