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
[{'content': 'Pyruvate can be converted into all of  the following in a single step except: \nSelect and explain. \nA. Phosphoenol pyruvate, B. Alanine, C. Acetyl CoA, D. Lactate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]