Chimpanzees Austin and Sherman (Savage-Rumbaugh Et Al

Chimpanzees Austin and Sherman (Savage-Rumbaugh et al. 1978) , when tested for their ability to use lexigrams to specify which of several foods was in a container when only one of them had observed the container being baited,

A) could still convey the correct information to one another even when they were prevented from using the keyboard.
B) were able to communicate the information effectively to one another regardless of which of them was the observer.
C) were successful in their communication attempt only if the experimenter also knew the identity of the food.
D) were successful only when they were kept in separate rooms so they didn't fight over the food.