Concerning Shift Assignment of Patrol Officers, a PERF Report Concluded

Concerning shift assignment of patrol officers, a PERF report concluded that

A) in order for officers to know every district in town, officers should rotate districts once every three months.
B) in order to be fair to other officers, patrol officers should rotate shifts once every three months.
C) frequent change of shifts is deleterious to the physical and psychological health of an officer.
D) shift work has no effect on officers' health and job performance.