In an experiment, laboratory rats were classically conditioned to get sick after drinking sweetened water that was paired with a drug that compromises immune response. These rats continued to die after the experiment because of the conditioned response to the sweetened water alone.

Which conclusion can be drawn from this research?

(A) Animals and humans can be classically conditioned to any neutral stimulus
(B) Any response the body is capable of making can be conditioned, including dying
(C) Classical conditioning is always automatic and cannot be avoided with strategies
(D) Classical conditioning works with voluntary responses as well