Three allopatric species of cat native to Israel are also highly sexually dimorphic, resulting in six unique morphotypes. Each of these has teeth whose size distributions overlap very little where species co-occur, but are much more variable where no other species occur. What is the most plausible hypothesis to explain this pattern?

These species likely compete for limited resources (i.e., food, space, etc).  Moreover, in the zone where distributions overlap, it is likely that the allopatric species compete for the same type of food, which makes that those cats with a specific teeth size have a better chance of survival, thereby reducing the phenotypic variation associated to this trait

the answer for this question would be d. glaciers