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: Biochemistry
Catecholamines are synthesized from ? 
Select and explain. 
A. Tryptophan, B. Tyrosine, C. Methionine, D. Histidine
B: Tyrosine
Answer: B: Tyrosine 
Explanation: Ans. is 'b' i.e., Tyrosine Catecholamines (epinephrine, norepinephrine and dopamine) are synthesized from tyrosin. Has been explained in previous seesions.