Millions of years ago, seawater flooded part of the Mississippi River Valley. Scientists have concluded that chorus frogs were affected by the flooding. The flooded areas formed geographic barriers between chorus frog populations for millions of years. Which of the following most likely occurred as a result of the seawater flooding?A. The frogs lost the tadpole stage of their life cycle. B. Isolated populations of frogs became separate species. C. The frogs’ eggs were fertilized by sperm of marine species. D. Frog populations were protected from all the predators in their areas.