Which term describes animals under the category "equine"?

The term "equine" specifically refers to animals that belong to the family Equidae, which includes horses, donkeys, and zebras. However, in common usage, when categorizing the most widely recognized representatives of this group, "equine" is predominantly associated with horses. Therefore, when identifying the correct answer from the options given, "horse" is the most appropriate choice because it directly exemplifies the equine category.

In contrast, donkeys, while also part of the equine family, are less commonly referred to specifically as equine in general discussions. The other options, such as sheep and cattle, belong to entirely different animal families—Caprinae and Bovidae, respectively—and therefore do not relate to the equine classification at all. Thus, "horse" stands out as the clear representation of the equine category.