Answer: Sympatric speciation
Step-by-step explanation:
Speciation is a phenomena in which a new species develop from the parent species due to reproductive isolation.
Sympatric speciation is a speciation in which a new species develop from the ancestor species in the same geographical location. In this a speciation occurs due to change in the behavior, adaptation and other features which brings reproductive isolation between the two populations of the species.
The given situation is the example of the sympatric speciation. This is because of the fact that a new species emerged when feeds only upon the apples instead of the hawthorns developed at the same geographical location. This is due to the change in type of food choice.