The five-kingdom system of classification reflects the idea that all organisms can be separated into two main groups: prokaryotes and eukaryotes. The new six-kingdom system recognizes three broader groups that include six kingdoms. How do the three basic groups of the six-kingdom system differ from those of the 5-kingdom system? A) The six-kingdom system has three domains in order to includes a new kingdom for viruses. B) The six-kingdom recognizes the vast differences in protists and divides them into two kingdoms. C) The six-kingdom system has three domains: two domains separate all prokaryotic organisms into two new groups. D) The six-kingdom system adds a broader classification of domain to divide all living things into three groups: microorganisms, plants, and animals.