Which Condition Is Least Likely to Lead to Geographic Isolation

Which condition is least likely to lead to geographic isolation and allopatric speciation?

A) An eight-lane highway dividing a population of snails with limited mobility
B) A narrow,but deep,river dividing a population of hummingbirds
C) A narrow,but deep,river dividing a population of white-footed mice (not known for their swimming ability)
D) A patch of land bisecting a river and dividing a population of minnows
E) A mountain range dividing a population of moths