Which of the following combinations will show vasomotor reversal of Dale
Adrenaline leads to increased BP by acting on α1 - receptors, and  vasodilation by action on β2 receptors. If it is administered after Phentolamine (α1 - blocker) it can lead to only vasodilation, which is termed as "Vasomotor reversal of Dale".
Phentolamine followed by adrenaline
Propanalol followed by adrenaline
Phentolamine followed by nor adrenaline
Propanalol followed by nor adrenaline