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: Physiology
A patient has been diagnosed with depression who responds well to MAO inhibitors. Neurotransmitter which is deficient in this patient is produced from ____ 
Select and explain. 
A. Raphe nucleus of Pons, B. Substantia Nigra, C. Locus Ceruleus, D. Hypothalamus
C: Locus Ceruleus
Answer: C: Locus Ceruleus 
Explanation: This patient with depression responds to MAO inhibitors. Hence neurotransmitter deficient is Norepinephrine which is produced by Locus Ceruleus.