when the pressure drops only one of the following does not occur: 1) Vasoconstriction of the veins 2) Increase the frequency of the heart 3) vasodilation of the arterioles 4) Increase the strength of the heart's contractility 5) stimulation of the vasoconstrictor part of the vasomotor center
Actually your answer as 3 is right. Because vasodilatiton of arterioles is actually the cause of the pressure drop because it reduces the resistance. all other options try to raise the pressure.