The change in the environment affected how the organism would evolve to be so that it could survive. the term for that is survival of the fittest, and only the fittest would be able to survive the conditions of its surrounding environment. hope this answered your question. :)
Answer:
The correct answer is C) There is a larger variety of MHC proteins that can be expressed on the cell surfaces of their immune cells, providing a wider opportunity to recognize and attack pathogens.
Explanation:
The best description about the brain stem is: it is the most important organ of our body's survival. It connects the brain and the spinal cord, controls the vital organs like the lungs and heart and it also coordinates the many essential body reflexes.
The answer to the question is C.