Option b is correct: The present study examined the use and making of tools to obtain foodstuffs in artificial-mound holes by five captive, group-living Sumatran orangutans (Pongo pygmaeus abelii). Three adult orangutans frequently stripped leaves and twigs from a branch provided (tool-making), and then inserted the tool into a hole to obtain foodstuffs (tool-using). When the orangutans were unable to insert a tool into a hole, they usually modified the tool and/or changed their tool-using technique, such as changing how they grasped the tool.

Source: https://www.newscientist.com/article/2308133-orangutans-can-learn-how-to-use-stone-tools-as-hammers-and-knives/

https://pubmed.ncbi.nlm.nih.gov/14744550/