What is natural selection?

Explanation:

the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.

basically, this means that animals would technically evolve depending on their environment

ex: if there were animals living on top of a mountain where it it cold, the animals would tend to have furs

I hope this helps

it enhances antibody production by t cells of the adaptive immune system.

hope i'm right

explanation:

"a.) well–developed vascular system."