C) is the best answer because atmosphere deals with gases and hydrosphere deals with water.
Hope this helps... BTW you took out (water) in the question C
A mutation is a change in trait. For example people who are lactose intolerant are normal, but people that can can drink milk without a problem have mutated. Hopefully this makes sense and helped.
Genes they assort independently if they follow the 9: 3: 3: 1 rule resulting from a dihybrid cross.
It shows that the genes are not on the same chromosome and they are not included.
