Answer:
The correct answer would be behavioral.
Behavioral reproductive isolation is one of the methods that lead to speciation.
It is a type of prezygotic isolation in which species are isolated through differences in the mating signals and rituals.
For example, a particular pattern of dance, songs et cetera.
Similarly, jumping of a male bird in the opposite direction would not be recognized by the female bird due to which they would not be able to interbreed.