This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Introduction to Central Nervous System, Subject name: Physiology
Commonest inhibitory transmitter in the spinal cord is: 
Select and explain. 
A. GABA, B. Glycine, C. Substance P, D. Aspaate
B: Glycine
Answer: B: Glycine 
Explanation: GABA and glycine are the most common inhibitory transmitters in the CNS.