Answer:
a) Maintenance stage
Step-by-step explanation:
The stages of change model are pre-contemplation stage, contemplation, determination, action, relapse, and the maintenance stage. In the maintenance stage, people are now able to sustain their change in behavior for a period of more than 6 months, and have a strong determination to maintain the change in behavior. Bob, just like people in this stage of change is reinforcing himself by buying new CDs each month in order for him not to relapse to earlier stages of change.