Some Finches on the Galápagos Islands Eat Insects,an Unusual Food

Some finches on the Galápagos Islands eat insects,an unusual food for finches to eat.These finches

A) evolved from a lineage of birds other than finches that ate insects.
B) learned their habits from local birds.
C) switched to insects because they tasted better than their usual food.
D) fill roles that birds other than finches would fill in other places.