The organism possesses several mechanisms to control blood pressure, the main mechanisms are the quantity of blood pumped by the heart, artery diameter, and the volume of blood in the bloodstream. In the last case, we have that when there is an increase in volume, there is an increase in blood pressure, this means that the relationship is a positive relationship as one increases the other will too, and if one decreases the other will decrease too. Therefore we can say that the correct answer is Drecrease, decrease.