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
Mechanism of action of tetanospasmin 
Select and explain. 
A. Inhibition of GABA release, B. Inhibition cAMP, C. Inactivation of Ach receptors, D. Inhibition of cGMP
A: Inhibition of GABA release
Answer: A: Inhibition of GABA release 
Explanation: Ans. is 'a' i.e., Inhibition of GABA release . Tetanospasmin blocks the release of inhibitory neurotransmitters (GABA and glycine) in brain-stem and spinal cord.