At the Beginning of the School Year,Mr

At the beginning of the school year,Mr. Webber is concerned that Frances rarely does her independent seatwork. He begins praising Frances for each seatwork assignment she completes,and by January she is completing her assignments regularly. To make sure that the behavior continues in the years to come,what would operant conditioning theorists tell Mr. Webber to do now?

A) Praise her more often than before.
B) Praise her for only some of her completed assignments.
C) Punish Frances when she doesn't complete an assignment.
D) Switch from a social reinforcer to a concrete reinforcer.