This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
A 25 year old man with a psychotic illness, was treated with haloperido130mg/day. On the third day, he developed pacing, and inability to sit still in one place. The medication likely to be helpful is - 
Select and explain. 
A. Phenytoin, B. Propranolol, C. Methylphenidate, D. Trihexyphenedyl
B: Propranolol
Answer: B: Propranolol 
Explanation: Restlessness (inability to sit still) and pacing suggests the diagnosis of Akathesia.
The drug of choice for Akathesia is one of the β-blocker.