What Were the Results of Studies Beginning in the 1920s

What were the results of studies beginning in the 1920s, in which chimpanzees were raised by psychologists in their homes?

A) The chimpanzees developed the ability to use availability heuristics, but not representativeness heuristics.
B) The chimpanzees showed only limited understanding of language, and were not able to speak.
C) The chimpanzees became increasingly violent and aggressive, and had to be returned to their colonies.
D) The behavior of the chimpanzees remained unchanged, but the families began to eat a lot of bananas and groomed each other.