Which of the following best describes the mechanism behind the change in beak size in the finch population?
- A The formation of two new finch species from a single parent species.
- B A change in gene frequencies in the finch population due to selective pressure from the environmental change.
- C A new allele appearing in the finch population as a result of mutation.
- D The achievement of dynamic equilibrium in the finch population as a result of homeostasis.