Final answer:
The term "catus" in the scientific name Felis catus is the species.
Step-by-step explanation:
The term "catus" in the scientific name Felis catus of the house cat represents the species. When we refer to an organism's scientific name, using binomial nomenclature, the first word indicates the genus and the second word indicates the species. In this case, Felis is the genus, and catus is the species. The classification system is hierarchical, with species being the most specific level. Therefore, the correct answer to the question is A) species.