The author mentions the "sophisticated climbing skills" of chimpanzees most likely in order to present information that to
a. explain why chimpanzees are less vulnerable to predation by leopards than are diana monkeys
b. question the hypothesis that diana monkeys hide in the forest canopy to defend themselves from chimpanzees
c. argue that the antipredator strategies diana monkeys use to defend themselves against chimpanzees
d. suggest a possible reason for chimpanzees' and diana monkeys' use of similar antipredator strategies to defend themselves against leopards