Final answer:
Reinforcing internal rewards is most appropriate during the maintenance stage of change, focusing on long-term behavior sustainability and personal satisfaction over external reinforcement.
Step-by-step explanation:
Reinforcing the need for a transition from external to internal rewards would be most appropriate at the maintenance stage of change. During the maintenance phase, individuals work to consolidate the gains they have made during the action stage and prevent relapse. This stage is about sustaining new behaviors over the long term, where internal rewards, such as a sense of achievement and personal satisfaction, become more important than external rewards like praise or prizes. Effort and compensation principles suggest that rewards should reflect the effort put in and the costs incurred. However, as changes become ingrained, the intrinsic rewards align with the values and personal goals that motivate continuing the new behavior without the need for external reinforcement.