This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology and Reproduction, Subject name: Physiology
Vasomotor reversal of dale is demonstrated by 
Select and explain. 
A. Fall in blood pressure by high dose intravenous Ach, B. Increase in blood pressure following administration of IV propranolol, C. Fall in blood pressure by ganglionic blocker, D. Fall in blood pressure by adrenaline pretreated with phentolamine
D: Fall in blood pressure by adrenaline pretreated with phentolamine
Answer: D: Fall in blood pressure by adrenaline pretreated with phentolamine 
Explanation: Ans. (d) Fall in blood pressure by adrenaline pretreated with phentolamine(Ref: Ganong, 25th ed/p.353)If the subject is given a blocker and then if epinephrine is injected, vasodilation and decrease in BP is seen. This effect is called "Vasomotor reversal of Dale"