This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
Drug of choice in drug induced parkinsonism is 
Select and explain. 
A. Levodopa, B. Benzhexol, C. Selegilline, D. Amantadine
B: Benzhexol
Answer: B: Benzhexol 
Explanation: (Benzhexol) (421-KDT 6th)* Trihexyphenidyl (Benzhexol) is most commonly used drug in drug induced Parkinsonism* "Anticholinergics are the only drugs effective in drug (phenothiazine) induced parkinsonism "Drug used in Alzheimer's disease Acetylcholinesterase inhibitors - donepezil, galentamine, rivastigmine, tacrine NMDA receptor antagonists - Memantine