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: Physiology
Endothelium derived relaxing factor (EDRF) induced vasodilatation is mediated by: 
Select and explain. 
A. Increased intracellular cGMP, B. Decreased intracellular cGMP, C. Increased extracellular cyclic AMP, D. Decreased intracellular cyclic AMP
A: Increased intracellular cGMP
Answer: A: Increased intracellular cGMP 
Explanation: Endothelial cells produce endothelium ­derived relaxing factor (EDRF), a substance that is now known to be nitric oxide (NO).
NO and ANP hormone act via increasing intracellular cGMP.