Two Populations of Snails Are Allopatric, Living in Areas That

Two populations of snails are allopatric, living in areas that have different compositions of soil types.The snails live in soil and are not very mobile.Researchers are interested in whether the populations have acquired different types of reproductive isolation.What would be the best way to test whether these populations exhibit habitat isolation?

A) Examine the preference of soil types of each population. If they have similar preferences, then they likely exhibit habitat isolation.
B) Examine the preference of soil types of each population. If they have different preferences, then they likely exhibit habitat isolation.
C) Observe when each population is active. If they are active at very different times, then they likely exhibit habitat isolation.
D) Observe when each population is active. If they are active at the same time, then they likely exhibit habitat isolation.
E) Bring them into the lab. Have the females from one population mate with males from another. Count the number of offspring. If few offspring are produced, then they likely exhibit temporal isolation.