Assuming that people act in rational ways, what psychological model of health behavior specifies several factors that determine whether a person is likely to change behavior when faced with a health threat

Health Belief Model.

Explanation:

Health Belief Model is the model, according to which scientists analyze the behavior of people. People change their health behaviors only when they think they are at risk, or they change to avoid the consequences.

This model was developed to promote health, to prevent disease from spreading, and also to predict health behaviors.

So, the correct answer, according to the definition provided is 'Health belief Model'.