Finches developed special beaks that help them eat either insects or seeds, depending on which is more plentiful in their area. Why is this a good example of an adaptive function? A.
There is a lot of variation in beak type.

B.
Different beak types make finches less likely to be eaten by a predator.

C.
Finches learned to communicate about food options.

D.
Different beak types help the finches survive in their environment.