Answer:
c. capillary
Step-by-step explanation:
Capillary -
Capillaries are the small blood vessels with diameter of 5 to 10 micrometres .
In the body , the capillary are the smallest blood vessels .
The main function of capillaries is to exchange substance along with the interstitial fluids .
Substance like , water , glucose , oxygen carbon dioxide , nutrients etc .
Hence , from the information from the question , the answer is capillaries .