Which of the following is the best way to create a new species? combine the genes from two different population or lower the genetic diversity of a population

You would need to combine the genes from two different populations. Since lowering the diversity of a population with cause there to be no variation. Which means that then the population cannot evolve in different ways such as to changing environmental factors and can face an extreme risk of extinction. I hope this helped!

Homologous chromosomes with heterozygous alleles d) heterozygous chromosomes with homozygous alleles