Answer:
B. comparative method
Step-by-step explanation:
Comparative method is a form of investigative technique used by scientists to learn the morphological traits (particular features) of one specie by studying the traits of a closely related specie. In other words, it involves drawing evidences from a wide range of closely related organisms to make inferences about another organism.
For example, comparative method have been used to study the large testicle size of chimpanzees by comparing with gorillas which is a closely related specie.