This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
All of the following are essential amino acids except: 
Select and explain. 
A. Methionine, B. Lysine, C. Alanine, D. Leucine
C: Alanine
Answer: C: Alanine 
Explanation: C. AlanineEssential (MettVilPhlyRead As Met Will Fly)All the other amino acidNonessentialMethionineArginineAll the other amino acidThreonine Tryptophan Valine Isoleucine Leucine Phenylalanine Lysine