Harold is aware that cigarette smoking makes him susceptible to developing lung cancer. further, he is aware that lung cancer is a serious and life threatening illness. he also believes that quitting smoking would reduce his risk of lung cancer. according to what theory of behavior change is harold is likely to make a behavior change:

Health Action Process Approach

Explanation:

The health action process approach  a sequence of two continuous self-regulatory processes. It has a goal-setting phase (motivation) and a goal-pursuit phase (volition); the second phase is subdivided into a pre-action phase and an action phase. Motivational self-efficacy, outcome-expectancies and risk perceptions (in this case Harold's situation) are assumed to be predictors of intentions. The predictive effect of motivational self-efficacy on behaviour is recovery self-efficacy, and the effects of intentions are assumed to be mediated by planning. The latter processes refer to the volitional phase of the model.