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
Epinephrine is formed from? 
Select and explain. 
A. Methionone, B. Tyrosine, C. Valine, D. Glycine
B: Tyrosine
Answer: B: Tyrosine 
Explanation: Tyrosine is the precursor for the synthesis of catecholamines namely dopamine, epinephrine and norepinephrine.