Farmers living near Yellowstone National Park have hunted wolves to protect their farm animals from predation. Now, there are no more wolves in the ecosystem. What effect does returning the wolves to the ecosystem have on the rest of the populations of animals in Yellowstone National Park? (science)

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.