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
What is involved in formation of d-TMP from d- UMP? 
Select and explain. 
A. N5, N10-methylene tetrahydrofolate, B. Formimino folate, C. N5 formyl folate, D. Dihydrofolate
A: N5, N10-methylene tetrahydrofolate
Answer: A: N5, N10-methylene tetrahydrofolate 
Explanation: Conversion of dUMP to dTMP requires N5, Nw-methylene H4 folate.