The possible answers are :
A) a video that shows a large river that has penguin populations on both sides B) a video that shows penguin species that have different mating dances
C)a video that shows a penguin that is laying eggs
D)a video that shows penguins in a tidal pool and an open ocean
The correct answer is B
When there is a reproductive isolation between two species this means that they are unable to mate and leave offspring.
The isolation barrier may exist before fertilization (different reproductive behavior) or after fertilization (inviability of the embryo).
In this case, the reproductive barrier is shown the different mating dances