I would say C if thats not right then its problable D
The answer would be A. a virus
The question states that the blood was filtered thru a porous material that prevented <u>all cells </u>from passing thru.
All of the options are cells except viruses.
Hope this helps:)
Anticoagulants such as heparin or warfarin (also called Coumadin) slow down your body's process of making clots. Antiplatelet drugs, such as aspirin, prevent blood cells called platelets from clumping together to form a clot. When you take a blood thinner, follow directions carefully.
i believe the answer is "A fundamental role". hope this helps.