Final answer:
Bufo americanus is most closely related to the American Toad
Step-by-step explanation:
The animal that is most closely related to Bufo americanus is the American Toad (c).
The reason for this is that Bufo americanus is the scientific name for the American toad. The other options, such as the American Robin, American Bison, and American Alligator, belong to different animal groups and are not closely related to toads.
Therefore, the American Toad is the correct answer.