The curve on the left shows the height of a population of penguins . the curve on the right shows the population five years later. what has happened to this population

The type of natural selection demonstrate is B. stabilizing selection.
There are different types of natural selections, each affecting the population density of a specific allele in a different way. In stabilizing selection, the non-extreme trait is maximized. This is seen in the curve as there is less population observed at the extreme ends of the spectrum but a greater population lying in the average, less extreme zone.