Bart Used to Work Out After Work Nearly Every Day,and

Multiple Choice

Bart used to work out after work nearly every day,and his trainer would give him a lot of encouragement and support.Lately his trainer has been ignoring him,and Bart has been going to the gym a lot less frequently.Which process does this example illustrate

A)  extinction 
B)  avoidance 
C)  resistance 
D)  punishment