A supervisor is trying to make his new assistant manager Roger more assertive in dealing with his co-workers. For the first couple of weeks, every time Roger issued an order or made a decision based on what is good for the company rather than in accordance with the wishes of the co-worker making the request, Roger's supervisor congratulated him. With such positive reinforcement, Roger has begun to assume a more managerial role. This is an example of:

a. Shaping.

b. Enactive mastery.

c. Knowledge management.

d. Behavior modeling.

e. Task segmentation.