Which of the following enzymes require Vitamin C for their activity?
Vitamin C plays the role of a coenzyme in hydroxylation of proline and lysine while protocollagen is converted to collagen  (i.e.  post-translational modification). The hydroxylation reaction is catalysed by lysyl hydroxylase  (for  lysine)  and prolyl  hydroxylase (for  proline).
Procollagen proline hydroxylase
Procollagen amino peptidase
Procollagen carboxyl peptidase
Lysyl oxidase