<prompt> Hydroxylation of proline in collagen requires which of the following:Vitamin CFe2a-ketoglutarateAll of the above  <response>: Ans. D. All of the aboveProline and Lysine are hydroxylated to form hydroxyl proline and hydroxyl lysine in the presence of enzyme hydroxylase and requires Fe2 ascorbic acid Vitamin C, oxygen and a- ketoglutarate. 