Albumin will increase the oncotic pressure of blood. Because it stays in your vasculature for a while, it should draw extravascular fluid into your circulation, increasing your blood volume.
Increases in the volume of circulating blood increase venous return, and in turn increases cardiac output via the Frank-Starling relationship, increasing blood pressure (assuming stable systemic vascular resistance: mean arterial pressure is proportional to cardiac output * SVR).
This is probably beyond the scope of MCAT.