"participants from a self- study are re-evaluated after 2 years, and the results reveal that those who experienced a slower reduction of stress levels since the study conclusion showed a significant decrease in their use the coping strategies learned in the study. what psychological phenomenon best explains this change? "

The psychological phenomenon that best explains the change is that of prospective forgetting.

Explanation:

As a part of human fallibility, some people tend to unknowingly opt to live according to their older routines in a few days after trying to bring a change in their lives. This unknowing shift backward is in psychological terms referred to as prospective forgetting. In this type of forgetting, the person is unaware of the changes that are happening slowly and gradually.