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: Radiology
Drug used as pharmacological stress in stress echo 
Select and explain. 
A. Dopamine, B. Dobutamine, C. Isoprenaline, D. Nitroprusside
B: Dobutamine
Answer: B: Dobutamine 
Explanation: Pharmacological stress : Dobutamine.
Physiological stress : Ttreadmill or bicycle exercise.