This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
Number of neurons in enteric nervous system 
Select and explain. 
A. 100 million, B. 10 million, C. l million, D. l lakh
A: 100 million
Answer: A: 100 million 
Explanation: The ENS consists of some 100 million neurons, one-thousandth of the number of neurons in the brain, and about one-tenth the number of neurons in the spinal cord. The enteric nervous system is embedded in the lining of the gastrointestinal system. Ref: guyton and hall textbook of medical physiology 12 edition page number:442,443,444