I would say D it seem to be the likely choice but not a 100%
The immune system is the bodies defense against invaders and is located in all body tissues with concentration in the mucosal surfaces and skin.
Non-disjunction occurs when a the chromosomes do not split properly during meiosis resulting in too few chromosomes I believe.
Populations evolve and individual organisms do not. Evolution occurs through natural selection and survival of the fittest as populations evolve traits that better suit their environment.
Answer: A. Average rainfall has decreased
Explanation:
I might be wrong. sorry if i'm wrong