Definition: You are given a question on clinical knowledge. You are also given 4 answer options (associated with "A", "B", "C", "D"), out of which only one is correct. You need to answer the question by selecting the correct option. You should only answer with the choice letter, not the whole answer.
Input: What commonly causes skin excoriation?
(A)A well-fitting pouch. (B)Changing the pouch every day. (C)Leakage of effluent onto peristomal skin. (D)The use of unscented soap to cleanse the skin.

C