Assume That the Starting Cell or Parents of the Bacteria

Assume that the starting cell or parents of the bacteria and housefly populations in the question above were well adapted to their environment. Now imagine that the populations are subjected to very different environment. How do you think these two populations may respond to the environmental change?

A) It's more likely that the housefly population will contain some genetic variants that are better adapted to the new conditions than the bacterial population.
B) Both would prosper because every individual would generate new beneficial mutations.
C) The bacteria would prosper because they are simpler organisms than a housefly.
D) Both would die out because there would be no genetic variants suitable for the new conditions.
E) It's more likely that the bacterial population will contain some genetic variants that are better adapted to the new conditions than the housefly population.