It seems that you have forgotten the given choices for this question. But anyway, here is the answer. When Linnaeus began classifying organisms in the 1700s, he categorized them as plant, animal, or mineral. These kingdoms were later revised to exclude minerals and expanded to include animals, plants, fungi, protists, and bacteria. The statement that best explains a reason for this change is technological advances led to the discovery of single-celled organisms and increased our understanding of relationships between organisms.