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
Coronary vasodilatation is caused by: 
Select and explain. 
A. Adenosine, B. Bradykinin, C. Histamine, D. Ergotamine
A: Adenosine
Answer: A: Adenosine 
Explanation: None