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 amino acid is purely Ketogenic 
Select and explain. 
A. Tyrosine, B. Leucine, C. Tryptophan, D. Isoleucine
B: Leucine
Answer: B: Leucine 
Explanation: Leucine and lysine are purely ketogenic, other amino acids given are both glucogenic and ketogenic.