blood banks platelets

What is the answer to this science question?
Blood is made up of several types of cells that are a liquid called ______, which is mostly water and make up more than half of the blood.
The word bank is
oxygen
aorta
plasma
capillaries
vavle
white blood cells
circulatory system
blood
vena cava
red blood cells
blood vessels
ventricle
platelets
artery
atrium
heart
veins
plasma
“These blood elements are suspended in blood plasma, a yellowish liquid that comprises about 55% of human blood” http://www.pbs.org/wnet/redgold/basics/bloodplasma.html
Want to help out more? — Platelet apheresis
Categories: Blood Banks