**Core Concept**
Vasomotor reversal of Dale refers to the phenomenon where an agonist, initially causing vasoconstriction, is followed by vasodilation due to receptor desensitization and subsequent activation of a different receptor subtype. This is a fundamental concept in pharmacology, specifically in the study of adrenergic receptors.

**Why the Correct Answer is Right**
The correct combination for vasomotor reversal of Dale involves an agonist that initially stimulates alpha-1 adrenergic receptors, causing vasoconstriction, followed by the activation of beta-2 adrenergic receptors, leading to vasodilation. This sequence of events is crucial for understanding the mechanisms behind vasomotor reversal.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it does not involve the sequential activation of alpha-1 and beta-2 adrenergic receptors, which is necessary for vasomotor reversal.
**Option B:** Incorrect because it does not accurately describe the phenomenon of vasomotor reversal, which involves a change from vasoconstriction to vasodilation.
**Option C:** Incorrect because it lacks the critical detail of receptor desensitization and the subsequent activation of beta-2 adrenergic receptors.

**Clinical Pearl / High-Yield Fact**
To remember the vasomotor reversal phenomenon, recall that alpha-1 agonists can cause vasoconstriction, but subsequent beta-2 agonism can lead to vasodilation. This sequence is crucial for understanding the complex interactions between adrenergic receptors and their effects on blood vessels.

**Correct Answer:** A. Phenylephrine followed by Isoproterenol