Assertion: When there is a fall in the blood pressure due to loss of blood volume, this is compensated by vasoconstiction of veins.
Reason: Veins hold the extra amount of blood which can be shifted to the arteries as required.
A. If both assertion and reason are true and the reason is a correct explanation of the assertion.
B. If both assertion and reason are true but reason is not a correct explanantion of the assertion.
C. If the assertion is true but reason is false.
D. If both the assertion and reason are false.
