This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
A 30 year old manic patient was prescribed haloperidol 3month back. For last two days he has become restless and kept pacing in he room for a day. On examination he was found to have tremors of hand. He is most likely to be suffering from: 
Select and explain. 
A. Anhedonia, B. Dystonia, C. Restless leg syndrome, D. Akathisia
D: Akathisia
Answer: D: Akathisia 
Explanation: Ref: KDT 8TH ED. Continous purposeless to and fro movement without anxiety is called Akathisia. It is an extrapyramidal syndrome caused by D2 blockers like haloperidol.