This question asks us to identify the scientist credited with introducing binomial nomenclature, the two-word naming system used for classifying living organisms. Instead of recalling the fact directly, we can work through each name and match it to the scientific contribution it is actually remembered for, ruling out anyone whose legacy lies elsewhere.
- Darwin: Charles Darwin's enduring contribution to biology is the theory of evolution by natural selection, laid out in "On the Origin of Species." His work explains how species change over generations, not how they are named. Since naming and classification are a separate branch of biology from evolutionary theory, this option can be ruled out.
- Linnaeus: Carl Linnaeus is the naturalist who created the hierarchical classification system still used today and, within it, formalised binomial nomenclature: giving every species a two-part Latin name made up of a genus and a species epithet (for example, Homo sapiens). This innovation, introduced in his work "Species Plantarum," is exactly the naming convention the question describes, which matches this option to the answer.
- Mendel: Gregor Mendel is remembered for his pea-plant breeding experiments that revealed the basic laws of inheritance, segregation and independent assortment. His focus was on how traits pass from parents to offspring, which has no connection to species naming, so this option is eliminated.
- Watson: James Watson, along with Francis Crick, is known for determining the double-helix structure of DNA, a discovery in molecular biology rather than taxonomy. Since this contribution concerns genetic structure and not nomenclature, this option does not fit either.
Working through each name shows that only one of them is tied to the creation of the two-word naming system: Linnaeus.
Therefore, the correct answer is Linnaeus.