Four weeks after a myocardial infarction, a patient enters an outpatient physical therapy cardiac rehabilitation program. Now that the patient is in phase 2, what should be the predominant focus of the exercise sessions?

A. Low-level weight training using a starting weight at one repetition maximum

B. Circuit training using various upper extremity resistance devices

C. Continuous aerobic activities using large muscle groups

D. Recreational activities such as running and basketball