Some baby birds peck at a red dot under their parent’s beak. This triggers a gagging reflex in the parent. Which option describes how this behavior increases fitness?

The parent moves to cover the baby birds. The baby birds can remain warm.

The parent throws one of the baby birds out of the nest. This ensures that the remaining birds can survive.

The parent gets angry and goes into a protective mode. This ensures the baby birds are safe.

The parent regurgitates the partly digested food for the baby bird. The baby bird can eat this food.