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 groups of amino acids produce a common component of the TCA cycle? 
Select and explain. 
A. Alanine, isoleucine, leucine, lysine, B. Serine, asparagine, glycine, glutamate, C. Isoleucine, valine, methionine, D. Proline, leucine, tryptophan
C: Isoleucine, valine, methionine
Answer: C: Isoleucine, valine, methionine 
Explanation: None