What Advantage Do Peer Appraisals Have Over Other Types of Appraisals

What advantage do peer appraisals have over other types of appraisals?

A) Peers know the job better than most managers do.
B) Peers do not have a conflict of interest over honestly appraising a fellow employee.
C) Peers may have a more intimate view of the performance of fellow employees.
D) Peers don't have to worry about meeting standards for distributions.