A Patient Began Trihexyphenidyl (Artane) for Treatment of Drug-Induced Parkinsonism

A patient began trihexyphenidyl (Artane) for treatment of drug-induced parkinsonism. Which finding demonstrates a positive response to the medication?

A) Blood pressure returns to patient's normal range.
B) Gait is steady with decreased rigidity.
C) Patient reports fewer feelings of depression.
D) Patient has tremors with voluntary movement.