Chapter 6 discussed college students' metamemory about factors affecting memory accuracy. according to this discussion,

a. people have fairly accurate metamemory when the stimuli are pairs of words.
b. students usually believe that simple rehearsal is an effective way to study for an exam.

B. students usually believe that simple rehearsal is an effective way to study for an exam.

Explanation:

Metamemory is a type of metacognition which refers to the Socratic awareness concept that learning is a person's own memory capability and the process of learning and memory self-monitoring. This means that the students  are self-aware of their memory and therefore, they use their memory and form the learning process accordingly. Hence, the correct answer is that students usually believe that simple rehearsal is an effective way to study for an exam as they are self-aware of their memory and focus on self-monitoring.