This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Male Reproductive System, Subject name: Physiology
[{'content': 'What is the nongenomic effect of testosterone on vascular smooth muscle? \nSelect and explain. \nA. Vasodilation, B. Vasoconstriction, C. Increase in prostaglandins, D. Increase in estrogen receptors', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Testosterone causes vasodilation by inhibiting L-type calcium channels to inhibit calcium influx into the cells, thus causing vasodilation', 'role': 'assistant'}]