Answer : 1. "Arteries"
Explanation :

Answer: A) Arteries Explanation: We know that the circulatory system of our body is a loop. The Heart is the pump, the arteries and their smaller branches (arterioles) carry oxygen rich blood all through your body tissues from the heart and the veins and their smaller branches (venules) carry oxygen depleted blood and waste products back to the heart from all the body parts.