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
A patient, Sunder is admitted to the emergency with severe bradycardia following drug overdose. The concerned drug was being taken for hypertension. Which of the following cannot be the drug ? 
Select and explain. 
A. Clonidine, B. Hydralazine, C. Propranolol, D. Reserpine
C: Propranolol
Answer: C: Propranolol 
Explanation: None