Although many chimpanzees live in environments with oil palm nuts, members of only a few populations use stones to crack open the nuts. The likely explanation is that a. the behavioral difference is caused by genetic differences between populations. b. members of different populations have different nutritional requirements. c. the cultural tradition of using stones to crack nuts has arisen in only some populations. d. members of different populations differ in learning ability.

Verified step by step guidance

1. Identify the key behavior described: Chimpanzees in some populations use stones to crack open oil palm nuts, while others do not.
2. Consider the role of genetics: Genetic differences could influence behavior, but there is no direct evidence provided that genetic variation leads to differences in using tools like stones.
3. Evaluate the nutritional needs: Different nutritional requirements might influence behavior, but the use of stones is a specific technique rather than a dietary preference.
4. Analyze the possibility of cultural differences: Cultural traditions, such as tool use, can vary between populations and are often learned behaviors passed down through generations.
5. Conclude with the most likely explanation: The use of stones to crack nuts is probably a cultural tradition that has developed in only some chimpanzee populations, making option 'c' the most likely explanation.