Snail Species a Has a Shell That Spirals Counterclockwise,but a Mutation

Multiple Choice

Snail species A has a shell that spirals counterclockwise,but a mutation has caused some individuals to have a clockwise shell.The genitalia of the two versions are incompatible,leading some scientists to say that the clockwise snails are reproductively isolated.This is an example of

A) hybrid breakdown.
B) gametic isolation.
C) hybrid inviability.
D) mutational isolation.
E) mechanical isolation.