Final answer:
The Health Belief Model is the framework that explains how personal beliefs influence health behaviors by addressing four sets of beliefs: perceived susceptibility, perceived severity, perceived benefits, and perceived barriers, along with self-efficacy (option a).
Step-by-step explanation:
The model or theory that helps to understand how one can affect health behaviors by influencing four sets of beliefs is best called the Health Belief Model (HBM). The HBM is rooted in the understanding that a person's beliefs about health problems, perceived benefits of action and barriers to action, and self-efficacy can predict health behaviors.
The model posits that for individuals to take health-related action, they must believe they are susceptible to a condition (perceived susceptibility), the condition has serious consequences (perceived severity), taking action would benefit them by reducing susceptibility or severity (perceived benefits), and the barriers to taking action are outweighed by its benefits (perceived barriers).
Additionally, an individual's confidence in their ability to successfully perform an action (self-efficacy) plays a role in determining whether they will engage in a health-related behavior.
Hence, the answer is option a.