What Statement Best Captures a "Process-Oriented" Approach to Examining the Mechanisms

What statement best captures a "process-oriented" approach to examining the mechanisms underpinning the exercise and mental health relationship?

A) There is likely a single mechanism that explains this relationship.
B) Psychosocial mechanisms are likely most important in explaining this relationship.
C) Studying this relationship requires a model or framework that can integrate many potential mechanisms.
D) There are lots of potential mechanisms that explain this relationship.