This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Amino Acid Metabolism, Subject name: Biochemistry
Serotonin is synthesized from- 
Select and explain. 
A. Tiyrosine, B. Alanine, C. Tryptophan, D. Glycine
C: Tryptophan
Answer: C: Tryptophan 
Explanation: Ans. is 'c' i.e., Tryptophan o Hvdroxytryptamine (serotonin) is synthesized from tryptophan.