Falsify : liar : : a friend : care b lie : trust c steal : thief d approve : dislike

c steal : thief

Explanation:

Falsify is to a liar, what steal is to a thief, because a liar falsifies, and a thief steals. The relation between them is that of a doing and the doer, or an action and to what it is generally associated with. Falsifying is associated with liars, since they fake, or forge the truth into something untrue. Similarly, stealing is associated with a thief. It also makes the relation into one between an action and what is someone called while engaging in it.