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: Pharmacology
Exocytic release of ACH is blocked by ? 
Select and explain. 
A. Hemicholium, B. Botulinum, C. Alpha bungarotoxind, D. Vesamicol
B: Botulinum
Answer: B: Botulinum 
Explanation: Ans. is 'b' i.e., Botulinum ACETYLCHOLINE SYNTHESIS AND RELEASE Choline is actively taken up by the axonal membrane by Na+; choline cotranspoer. (Rate limiting step). This step is blocked by Hemicholinium. Choline is acetylated with the help of ATP and coenzyme 'A' by the enzyme choline acetyl transferase present in the axoplasm.