Answer:
c. the cultural tradition of using stones to crack nuts has arisen in only some populations.
Step-by-step explanation:
According to the passage above we are made to understand that many chimpanzees live in environments containing oil palm nuts but some members of only a few populations use stones to crack open the nuts this shows that the few population that use stones to crack open nuts learnt to use it because of the environment which they found themselves, also learning by association.