Answer:
Evolution.
Explanation:
The ground finch could not survive after the drought with the size of its beak.
The beak required in order to feed on the hard seeds needed to be stronger and longer.
Due to this, the finch beak evolved and developed into a stronger longer beak adapted to feeding on large hard seeds.
Without this evolution, all the finches left on the Galapagos island could face extinction out of starvation.
