When the effects of genes add up to make the phenotype, they are called additive genes.
Populations evolve and individual organisms do not. Evolution occurs through natural selection and survival of the fittest as populations evolve traits that better suit their environment.
It is the second option
Gg symbolises green color(because G is dominant so it will be green) and GG symbolises yellow( as there is no dominant trait present)
I'm not sure but but i think the answer will be:
A. additive genetic variance times the selection differential.