A 65-year-old patient with a history of osteoarthritis reports increased pain and stiffness in the knees, particularly in the morning and after prolonged inactivity. Which intervention is most appropriate to recommend to this patient to help alleviate these symptoms?

B Increase dietary intake of calcium and vitamin D supplements. C Avoid all physical activity to prevent further joint damage. D Apply heat therapy to the affected joints before engaging in physical activity. A Initiate high-intensity weight-bearing exercises.