A Population of Hummingbirds with a Variety of Beak Sizes

Multiple Choice

A population of hummingbirds with a variety of beak sizes finds a new food source in a plant that has a long trumpet flower with nectar at the bottom of the trumpet. Over time, these hummingbirds develop longer beaks. This is an example of

A) directional selection.
B) stabilizing selection.
C) disruptive selection.
D) sexual selection.
E) genetic drift.