The correct answer is A.primary, because a primary landform is a natural feature on earth's surface.
Answer:
from precipitation, oceans lakes streams and soil
If all humans had the same DNA, and one person got the cold, everyone would die at some point. The more diversity there is the more chance of surviving an outbreak or natural disaster or something. Think of the flu. there are HUNDREDS of strains out there. some are resistant to our medicines and others aren't.
