After the Drought of 1977, Researchers Hypothesized That on Daphne

After the drought of 1977, researchers hypothesized that on Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. If this hypothesis is true, what would you expect to observe if a population of these medium ground finches colonizes a nearby island where T. cistoides is the primary available food in all yea
Assume that 1) even the survivors of the 1977 drought sometimes had difficulty cracking the tough T. cistoides fr and would eat other seeds when offered a choice, and 2) food availability is the primary limit on finch fitness on this new island.

A) evolution of smaller, pointier beaks over time
B) random fluctuations in beak size and shape
C) evolution of yet larger, deeper beaks over time
D) no change in beak size and shape