Venoconstriction the amount of blood within the venous system, which the volume in the arterial and capillary systems.

Venoconstriction reduces     the amount of blood within the venous system, which increases the volume in the arterial and capillary systems

Explanation:

Reflex venoconstriction is characterized as a smooth muscle neurogenically induced contraction in the walls of the veins; it causes a decrease in vascular ability that is seen as a decrease in the amount of blood kept at the same pressure, an increase in the amount of blood pressure at the same volume, or a combination of both.

The vasoconstriction mechanism results from increased calcium concentration (Ca2 + ions) within vascular smooth muscle cells. The basic mechanisms for generating higher intracellular calcium concentrations, however, depend on the vasoconstrictor.

Hence , the first answer is reduces and the second one is increases.

[content deleted] - user123802726recklesschicken

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.