What Was Especially Unusual About Loulis the Chimpanzee's Communication Abilities

What was especially unusual about Loulis the chimpanzee's communication abilities?

A) Loulis used an artificial language based on plastic symbols.
B) He was the first chimp who could follow simple written instructions.
C) Loulis was the first chimpanzee to understand and use sign language.
D) He learned sign language from other chimpanzees.