Instead of Referring to a Sample of Comments a Doctor

Instead of referring to a sample of comments a doctor has provided on his own website,Catrina has decided instead to rely on reviews from friends who have been his patients.What type of asymmetric information problem is Catrina trying to correct by soliciting comments from friends?

A) diminishing returns
B) adverse selection
C) moral hazard
D) principal-agent problem
E) an adverse selection problem that became a principal-agent problem