A 75-yrs-old woman with diabetes is taking an oral antidiabetic drugs. One day she goes without eating for 18 h. Her serum glucose concentration is 48 mg/dL (hypoglycemic) upon arrival at the emergency depament, where she is deemed to be in critical condition. Which of the following drugs most likely aggravated this fasting hypoglycemia?
Acarbose Glyburide Metformin Pioglitazone