What does adenine pair with in DNA?
adenine
guanine
cytosine
thymine

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.