The correct answer is D. Visible similarities and differences.
Step-by-step explanation
Organism classifications are a way of grouping organisms according to different characteristics of them. Previously there was the traditional classification, which was based on the visible similarities and physical differences of organisms, for example, plants, animals, microorganisms, among others. However, with scientific advances, more precise methods have been developed to classify organisms using genetics. So, the correct answer is D. Visible similarities and differences.