Answer:
D. When you are analyzing DNA of organisms
Step-by-step explanation:
Cladistics is focused on tracing common ancestors, which relies not only on physical characteristics but also DNA evidences. Cladistics is also known as modern taxonomy. Linnean taxonomy is more on the physical characteristics, which is also called traditional taxonomy. As technology progressed so did taxanomic categories, which allowed researchers to compare DNA to determine similarities in seemingly unrelated animals.