Directions: In the following question, four phrasal verbs are given. You are to choose the one which best expresses the meaning of the given word(s)/phrase/sentence.

Increase the rate of.

The phrasal verb "step up" means to increase the rate, intensity, or level of something. Option A "wind up" means to conclude or tighten, Option B "take aback" means to surprise, and Option D "step out" means to leave briefly or temporarily withdraw. "Step up" is used in contexts like stepping up production, stepping up efforts, or stepping up to a challenge.