A lone male wolf, who doesn't have a pack, travels the forest. When he reaches a new hill that he hasn't been on before, he spends a large amount of time sniffing the trees and rock outcrops. Finally, he turns and heads back from where he came, recognizing this is the territory of another wolf. What's most likely responsible for communicating this information to the wolf?
• A. Language
• B. The tracks of other wolves on the hill
• C. Pheromones
• D. Markings on the trees
L
