Answer:
b. Heart, arteries, capillaries, veins
Explanation:
A closed circulatory system allows blood flow to flow through the heart, arteries, capillaries and veins. This type of circulatory system is characterized by blood always circulating within the blood vessels.
The sequence of prayer, arteries, capillaries and veins can be found in humans, other vertebrates and even in ringworms and mollusks of the Cephalopoda class. Insects also have this type of circulation, but instead of blood they use a substance called hemolymph.
