Blood Flow Pathway in the Heart

Steps:

• Trace deoxygenated blood entering right atrium from body, moving to right ventricle, then to lungs via pulmonary artery.
• Follow oxygenated blood returning to left atrium from lungs, passing to left ventricle, then to body via aorta.
• Verify arrows show one-way flow through valves: tricuspid (right), mitral (left), preventing backflow.
• Confirm diagram aligns with systemic and pulmonary circulation loops.

Why B is correct:

• B depicts unidirectional flow from right side (deoxygenated) to lungs, then left side (oxygenated) to body, matching the heart's double-pump anatomy.

Why the others are wrong:

• A reverses left-to-right flow, ignoring oxygen-poor blood's entry on right.
• C shows bidirectional arrows in ventricles, violating valve function that enforces forward flow.
• D omits pulmonary circuit, depicting direct body-to-left atrium path without lung oxygenation.

Final answer: B