Cheng, male, 60 years old. Body fat, "three more and one less" symptoms are not obvious, long-term use of dietary treatment and oral hypoglycemic drugs to control blood glucose, but blood glucose control is not ideal. This should be considered first

A. Switch to insulin therapy
B. Increase exercise therapy
C. Increase the dose of hypoglycemic drugs
D. Adjust the time of medication
E. Hospitalized for further examination