Final answer:
Sunbathing is not a popular exercise program. Instead, aerobic exercises like swimming, anaerobic exercises like weight training, and moderate activities such as walking, are all considered beneficial exercise programs that contribute to physical fitness and health. Hence, option (d) is correct.
Step-by-step explanation:
The correct answer to the question “Which of these is not a popular exercise program?” is d. sunbathing. Sunbathing is not considered an exercise program; it is the practice of sitting or lying in the sun, usually to tan the skin. Exercise programs typically aim to enhance or maintain physical fitness and health.
Popular forms of physical exercise include aerobic exercises, like swimming (a), anaerobic exercises such as weight training (b), and moderate activities like walking (c). These activities are known to improve cardiovascular health, muscle strength, and endurance, and often recommend participation in moderate exercise for a minimum of 30 minutes a day, according to health guidelines.