Mr Billow Knows That the Students in His 11 Th

Mr. Billow knows that the students in his 11 th -grade history class are very friendly with each other and really like to do all of their assignments in groups. Thus, when a student does not bring in his homework completed, Mr. Billow makes him go to the library and work on an independent assignment. Mr. Billow's tactic is an example of which of the following?

A) Positive reinforcement
B) Negative reinforcement
C) Vicarious reinforcement
D) Punishment