What distinguishes Dall's sheep from Stone's sheep?

Dall's sheep and Stone's sheep can indeed be distinguished by both their horn curvature and the color of their coats.

Dall's sheep typically have more curved horns compared to the more straight or slightly curved horns of Stone's sheep. The curvature of the horns serves as a significant visual cue to differentiate between the two species, as the shape is a prominent and defining characteristic.

In addition to the horn structure, the coloration of their coats further differentiates them. Dall's sheep generally have a white coat, while Stone's sheep display a darker, brownish coloration. This difference in coat color is particularly noticeable and helps in identifying each species in their natural habitat.

Both these features—horn curvature and coat color—are essential identifiers when distinguishing Dall's sheep from Stone's sheep, making the option that includes both aspects the most comprehensive and accurate choice.