Schematic diagrams of two blood vessels are shown. Which labels are right?
- A1 aorta; 2 vena cava; 3 elastic fibres; 4 smooth muscle; 5 epithelium
- B1 artery; 2 vein; 3 collagen fibres; 4 smooth muscle and elastic tissue; 5 endothelium
- C1 vein; 2 artery; 3 collagen fibres; 4 elastic fibres; 5 squamous cells
- D1 coronary artery; 2 coronary vein; 3 elastic fibres; 4 smooth muscle and elastic tissue; 5 epithelium