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
Which of the following is not synthesised from tyrosine? 
Select and explain. 
A. Nor epinephrine, B. Melatonin, C. Thyroxine, D. Dopamine
B: Melatonin
Answer: B: Melatonin 
Explanation: None