Which two species are more closely related ursus maritimus ursus americanus or bufo americus?

Ursus maritimus (polar bear) and Ursus americanus (American black bear) are more closely related to each other than to Bufo americanus (American toad). Both polar bears and black bears belong to the same genus, Ursus, indicating a closer evolutionary relationship. In contrast, Bufo americanus belongs to a different class (Amphibia) and represents a distinct lineage from mammals.