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
Clonidine is used as an antihypertensive agent but if used as a fast intravenous injection, it can increase the blood pressure due to: 
Select and explain. 
A. Stimulation of vasomotor center, B. Release of noradrenaline from adrenergic nerve endings, C. Agonistic action on vascular α2 adrenergic receptors, D. Cardiac stimulation
C: Agonistic action on vascular α2 adrenergic receptors
Answer: C: Agonistic action on vascular α2 adrenergic receptors 
Explanation: None