What is one task that a peer reviewer is not likely to participate in?

A peer reviewer is not likely to be responsible for making the coffee or replacing the light bulbs in his laboratory.  

He is a "peer" (equal) of the scientist who published the research that he has been asked to review.  So he's likely to be one of the higher-ups in his own organization.

colorectal cancer may also develop from areas of abnormal cells in the lining of the colon or rectum. this area of abnormal cells is called dysplasia and is more commonly seen in people with certain inflammatory diseases of the bowel such as crohn's disease or ulcerative colitis.

object 2 because all the other ones are wrong