Which of the following interventions is most appropriate to prevent severe complications of chronic hyperglycemia in a patient with poorly controlled diabetes?

High-sugar snacks between meals to keep blood glucose fluctuating rapidly, which paradoxically reduces the chance of long-term organ damage by preventing sustained hyperglycemia.

Complete avoidance of exercise since exercise always increases blood glucose and will worsen long-term hyperglycemic complications.

Only intermittent fasting without medication or monitoring because short-term fasting alone will immediately reverse chronic hyperglycemic damage in organs and remove infection risk within days.

Tight long-term glycemic control through diet modification, regular physical activity, optimized medication regimen (e.g., insulin or other glucose-lowering agents), and regular monitoring to reduce risks of organ damage, infections, and dehydration.