One primary factor in speciation is...?

Question

a) unlimited resources
b) a population where no group is isolated form another
c) reproductive isolation, like a geographic barrier
d) temperate climatic conditions
e) organisms with little or no genetic variation

Answer 1

C. Isolation

If populations aren't isolated in some way, they just share any changes that occur and don't become different species.

Answer 2

c-repro isolation.