Answer:
( C ) Capillaries
Step-by-step explanation:
Capillary is the smallest blood vessels of the body , of 5 to 10 micrometres diameter.
These blood vessels forms a large network in the body.
The function of the capillaries is to exchange nutrients , oxygen , waste in between the blood and the tissues.
The blood flow in the body is as follows-
The blood flows from the heart via arteries , which further branches into arteriols , which further branches into capillaries , where the nutrients get exchanged .
After the exchange process is done , then the capillaries merge to become wide, venules , these venules further widen to become veins , and the blood is returned back to the heart by the vein , venae cavae.