Concept:Arteries carry blood away from the heart under high pressure; veins return blood to the heart under low pressure.Explanation:A. Correct: arteries have thick muscular walls and a narrow lumen; veins have thinner walls and a wide lumen.B. Wrong way round: arteries carry blood away from the heart, veins carry it to the heart.C. Wrong way round: most arteries carry oxygenated blood and most veins deoxygenated blood (the pulmonary vessels are the exception).D. Wrong way round: veins have valves; arteries do not.Answer:Option A (Arteries have relatively narrow lumen while veins have relatively wide lumen)