The correct response is: disruptive selection; two peaks at the extremes of the graph with a dip in the middle.
In the case of the peppered moth, disruptive selection occurs when both light and dark moths have a selective advantage in different environments, leading to the emergence of two distinct forms within the population. This results in a distribution curve with two peaks (one for light moths and one for dark moths) and a dip in the middle, indicating that the average (intermediate) moth coloration is less favorable in those differing environments.