Teachers who effectively shape their students' study habits are most likely to

A) avoid the use of negative reinforcement to motivate effective study.
B) reinforce effective study with primary rather than secondary reinforcers.
C) reinforce effective study on a fixed-interval schedule.
D) reinforce even minor improvements in students' study skills.

By reinforcing even minor improvements in students' study skills, teachers are more likely to shape and maintain those habits over time. This is because the reinforcement provides positive feedback and encourages the student to continue with the habit, rather than relying on negative reinforcement (such as punishment for not studying) or only reinforcing on a fixed-interval schedule. Primary and secondary reinforcers are not as relevant in this context, as the focus is on shaping study habits rather than rewarding with specific rewards.