Whenever students turn in their homework, a teacher rewards them with computer time. The more often they turn in their homework, the more they are allowed to use the computers. Students have been turning in their homework with increasing frequency. Thus, the computer time is serving as a(n):

a) punisher.

b) unconditioned stimulus.

c) reinforcer.

d) aversive stimulus.

c) reinforcer

Explanation:

A reinforcer, in operant conditioning, is a reward or positive consequence that is presented after a specific behavior occurs, and as such, the tendency of such behavior to be exhibited increases. For example, the computer time is a positive reinforcer presented to students as a stimulus, that increases the likelihood of the student turning in their homework more often.