Read the Scenario and Answer the Accompanying Questions

Multiple Choice

Read the scenario and answer the accompanying questions.
Today, finches occupy every continent except Australia, most eating seeds, a diet for which their bills are well-adapted. Over the past several million years, 13 Galapagos finches have come to occupy the varied Galapagos islands. Finches found on these islands have very different bill shapes and feeding behaviors than finches found on the nearby mainland. Darwin gathered a considerable amount of field data on these finches and their habitats in order to propose his findings.
-What major factors allowed the birds to adapt to their new environment?

A) genetic drift followed by mutation
B) mutation followed by reproductive isolation
C) mutation and disruptive selection
D) mutation and increased reproductive fit of some offspring
E) the founder effect followed by reproductive isolation