The problem-solving abilities of forest-dwelling chimpanzees are best illustrated by their naturally developed use of

A) sign language.
B) tools.
C) concepts.
D) outcome simulations.

Forest-dwelling chimpanzees are well-known for their use of tools, such as using sticks to extract ants from their nests or using stones to crack open nuts. This shows their ability to problem-solve and use resources in their environment to meet their needs. While chimpanzees have been taught some basic sign language in captivity, this is not a naturally developed ability in their wild forest habitat. Concepts and outcome simulations require a higher level of cognitive ability than has been observed in chimpanzees.