Sperm from a Slate-Pencil Sea Urchin Are Moved by the Ocean

Multiple Choice

Sperm from a slate-pencil sea urchin are moved by the ocean currents towards eggs from a rock boring sea urchin.The rock boring urchin eggs are fertilized,but only complete the first three rounds of embryonic cell division.What type of reproductive isolation is at work in this example?

A) mechanical isolation.
B) gametic isolation.
C) habitat isolation.
D) hybrid sterility
E) hybrid inviability.