B. sexual selection, which alters allele frequencies in the gene pool.
You're gonna have to give us a picture to support your question..
It is C. Nitrogen. Nitrogen is 78% of the atmoshere
Explanation:
The hydrologic cycle describes the pilgrimage of water as water molecules make their way from the Earth's surface to the atmosphere, and back again. This gigantic system, powered by energy from the sun, is a continuous exchange of moisture between the oceans, the atmosphere, and the land.