Answer: The correct answer is capillaries 
Explanation:
capillaries are tiny branched blood vessels that links arterioles to venules and allows exchange of nutrients and gases between the blood and its surrounding tissues
 
        
             
        
        
        
Answer:
c. population
Explanation:
 A localised group of organisms that belong to the same species is called Population. This can be a local population if the organisms stay at a particular place or a metapopulation if the organisms tend to move from one geographical location to another.