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
Cutaneous vasocontriction is mediated by 
Select and explain. 
A. Sympathetic adrenergic nerves, B. Sympathetic cholinergic nerves, C. Parasympathetic cholinergics, D. Somatic nerves
A: Sympathetic adrenergic nerves
Answer: A: Sympathetic adrenergic nerves 
Explanation: Noradrenaline acts on vascular smooth muscles to cause vasoconstriction. This is mediated by adrenergic sympathetic fibers.