The geosphere has four subsystems called the lithosphere, hydrosphere, cryosphere, and atmosphere. Because these subsystems interact with each other and the biosphere, they work together to influence the climate, trigger geological processes, and affect life all over the Earth.
I believe (B) is the best option due that it mentions the reason causing natural selection with limited supplies competition increases making it more likely for the strongest individuals to survive
Pairs of Chromosomes are called Sex cell pairs. Sex cells, like sperm and egg, have only a set of Chromosomes called "Daughter Cells". Sorry I didn't do all of your questions, I could only find some of the answers.