This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Methionine and Cysteine details, Subject name: Biochemistry
Taurine is synthesized from which amino acid? 
Select and explain. 
A. Tryptophan, B. PhenylAlanine, C. Cysteine, D. Alanine
C: Cysteine
Answer: C: Cysteine 
Explanation: Taurine, a major constituent of bile is synthesized from cysteine