Final answer:
The highest priority risk factor among those mentioned is uncontrolled hypertension, which can be immediately life-threatening and is modifiable through lifestyle changes and medication.
Step-by-step explanation:
When teaching a 68-year-old client who has multiple risk factors for cardiovascular disease, the highest priority for intervention should be uncontrolled hypertension (D). Hypertension greatly increases the risk of cardiovascular disorders and can significantly compound the effects of other risk factors. Furthermore, it is modifiable through both lifestyle changes and medication. Factors such as a sedentary lifestyle (C) and high cholesterol levels (E) are also important, and they can be modified by adopting healthy behaviors such as increased physical activity and dietary changes. While controlling Type 2 diabetes (F) and overweight/obesity (G) is also essential, the immediate effects of uncontrolled blood pressure are more acute. Although a family history of cardiovascular disease (A) is a significant risk factor, it cannot be modified. Similarly, a history of smoking for 30 years (B) has already contributed to the risk, but cessation would still benefit the client's overall health.