Heart's pumping action in circulation

Steps:

• Examine each option for accurate description of heart contraction, blood flow, and tissue exchange.
• Identify key processes: heart generates pressure for arterial flow to capillaries, forming tissue fluid; veins return blood.
• Eliminate garbled or factually incorrect statements about vessels, pumping, or diffusion.
• Confirm the option linking cardiac cycle to waste removal like CO2.

Why C is correct:

• The cardiac cycle (contraction and relaxation) circulates blood to remove waste molecules such as carbon dioxide from tissues into plasma for transport to lungs, per circulatory physiology.

Why the others are wrong:

• A: Arteries carry blood but do not pump it; heart provides the force.
• B: No "waste vessels"; statement is incoherent and misdescribes oxygen distribution and tissue fluid collection.
• D: Tissue fluid forms via capillary filtration but re-enters capillaries, not directly diffusing into veins.

Final answer: C