36.葉酸以輔酶型式參與人體的代謝作用,下列組合何者正確?(A)二氫葉酸(dihydrofolate)及DNA合成 (B)二氫葉酸(dihydrofolate)及胺基酸代謝 (C)四氫葉酸(tetrahydrofolate)及單碳代謝 (D)四氫葉酸(tetrahydrofolate)及轉硫作用