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
An essential amino acid in man is 
Select and explain. 
A. Aspartate, B. Tyrosine, C. Methionine, D. Serine
C: Methionine
Answer: C: Methionine 
Explanation: Isoleucine, Leucine, Threonine, Lysine, Methionine, Phenylalanine, Tryptophan, and Valine are essential amino acids.
Reference: Vasudevan 7th  ed, pg 27