Genome is to individual, as is to population: A. genotype B. phenotype C. gene pool D. heredity E. ecosystem

I think it might be C, as the genome is specific to an individual, so the gene pool is that for the population, I suppose.

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.