PLEASE ANSWER BY TODAY I AM DESPERATE!! WILL ALSO MARK AS BRAINLIEST! Compare and contrast two different Orders in taxonomy. Research different ones. What makes them different from each other?

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.