This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory chain, Subject name: Biochemistry
Which of the following enters the TCA cycle at succinyl - CoA? 
Select and explain. 
A. Tyrosine, B. Methionine, C. Tryptophan, D. Histidine
B: Methionine
Answer: B: Methionine 
Explanation: Valine Isoleucine Methionine conves to Propionyl CoA & then conves to Succinyl CoA & enters the cycle.Ref: DM Vasudevan Textbook of Medical Biochemistry, 6th edition, page no: 221