In Attempting to Study Police Officers' Attitudes Towards Their Supervisors,Les

Multiple Choice

In attempting to study police officers' attitudes towards their supervisors,Les surveys 25 police officers from the day shift.In order to ensure the finding has external validity,Les should

A) use a larger sample of officers from the day shift.
B) randomly assign officers to work under specific supervisors.
C) sample officers from all shifts in the department.
D) use confounding variables.