Higher Education System in India

Teaching machine is a device that presents series of problems and provides immediate “reward” or reinforcement to students when they give the correct answers to the posed question  i.e. get Feedback from students. 

                          Teaching machines are unique among instructional aids, in that the student not merely passively listen, watches, or reads but actively responds. And as he does so he finds out whether his response is correct or not. And a record may be kept which aids in improving the materials.  So answer is (B).