The correct answer would be D.
After many generations, only those with genes suitable to live in harsh environments can live. These genes are passed onto their offspring and then we see a rise in antibiotic resistant strains of bacteria such as Methicillin Resistant Staphylococcus Aureus (MRSA).
I think the correct answer from the choices listed above is option A. It is the alveoli that is composed of single layer <span>surrounded by a network of capillaries. These are used to allow oxygen and carbon dioxide to move from the lungs to the bloodstream.</span>
They will run out. Because nonrenewable means it can't be renewed until like millions of year or so. Hope this helps and You're Welcome! :3