In Studies in Which Researchers Have Attempted to Teach Apes

Multiple Choice

In studies in which researchers have attempted to teach apes to use a variety of sign languages:

A) some chimps have appeared to learn many words and combine words in appropriate ways
B) it has been proven that chimps are incapable of acquiring and using nonverbal communication
C) some chimps have achieved a level of language development that is equivalent to that of a 10-year-old child
D) chimps have acquired several signs but have never been able to use them to communicate successfully