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: Microbiology
Botulin toxin acts by: 
Select and explain. 
A. Decreases Secretion of Ach, B. Decreases Synthesis of Ach, C. Muscle nerve block, D. Inhibits Ach release
A: Decreases Secretion of Ach
Answer: A: Decreases Secretion of Ach 
Explanation: Decreases Secretion of Ach