The diagrams show cross-sections of three kinds of blood vessel. They are not drawn to scale. In what sequence will red blood cells pass through these vessels in the human body as they travel from the aorta to the right atrium of the heart?
- A1 → 2 → 3
- B1 → 3 → 2
- C2 → 3 → 1
- D3 → 1 → 2