Many researchers believe that the presence of RNA in brain cells is the biochemical basis

After an injection of RNA inhibitor, a wide range of behaviors in addition to the learned responses were affected.
B. After an injection of RNA inhibitor, animals that had not consistently been giving the learned responses were able to give them consistently.
C. After injections of RNA inhibitor, some animals lost memory of the learned responses totally but others lost it only partially.
D. After a small injection of RNA inhibitor, animals responded well, but as the size of the injection increased, they gave fewer of the learned responses.
E. After an injection of RNA inhibitor, animals could not learn a new response.