This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'What is involved in the formation of d-TMP from d-UMP? \nSelect and explain. \nA. N5, N10-methylene tetrahydrofolate, B. Form imino folate, C. N5 formyl folate, D. Dihydro folate', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The following reaction is catalyzed by thymidylate synthetase:5,10-methylenetetrahydrofolate + dUMP = dihydrofolate + dTMPBy means of reductive methylation, deoxyuridine monophosphate (dUMP) and N5, N10-methylene tetrahydrofolate together used to form dTMP, yielding dihydrofolate as a secondary product.', 'role': 'assistant'}]