The correct response is:
The white and yellow popkin population will grow, while the black and dark blue popkins will decrease.
This is because, under extremely hot conditions due to global warming, the black and dark blue popkins, which do not reflect sunlight well and get hotter, are likely to suffer from heat stress. This could lead to a decrease in their population. Conversely, the white and yellow popkins, which reflect sunlight better and may be better adapted to cope with the heat, are likely to thrive and increase in population.