Is there a way to know any test exam style questions for 9th grade biology because biology is a very complex subject and lots of information to learn and I want to study the key details thanks:D

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population. b) the separated population is small, and genetic drift occurs. c) the isolated population is exposed to different selection pressures than the ancestral population. d) different mutations begin to distinguish the gene pools of the separated populations. e) gene flow between the two populations is extensive.