Answer : The correct answer is -
1) A. allopatric speciation.
2)B. behaviorally isolated.
Allopatric speciation can be described as formation of new species when a biological population belonging to one species becomes geographically isolated and no gene flow occurs between the two during the course of evolution.
As per the given information in the question, a group of salamander population moved to east and another to west, which later evolved into two different population as they were unable to mate.
Thue, it represents allopatric speciation.
As the salamanders developed different reproductive behaviors, therefore it indicates behavior isolation, suggesting that they will perform different mating rituals.