This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Which of the following medications should not be given to a diabetic patient? 
Select and explain. 
A. Propranolol, B. Theophylline, C. Digoxin, D. Glyburide
A: Propranolol
Answer: A: Propranolol 
Explanation: Beta-blockers, such as propranolol, are contraindicated in diabetics because they are prone to hypoglycemic reactions. Blood sugar control is modulated by sympathetic-adrenergic control of the pancreatic islet cells. Glyburide, Heparin, and Digoxin and Theophylline are safe to use in diabetics. Ref: Westfall T.C., Westfall D.P. (2011). Chapter 12. Adrenergic Agonists and Antagonists. In L.L. Brunton, B.A. Chabner, B.C. Knollmann (Eds), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.