Dan and Dave Are Both College Graduates

Multiple Choice

Dan and Dave are both college graduates. Dan is a patrolman and Dave is a detective in the same police precinct. While Dan's job is inherently more dangerous than Dave's, Dave passed a difficult exam to gain promotion to detective. Dave earns more than Dan because

A) Dave's job is less dangerous.
B) of efficiency wages.
C) of education as a signal.
D) Dave has more human capital.