A researcher studying cats discovered that during the dream state of sleep, the cerebral cortex of a cats brain fires messages to its body as rapidly as it does during wakefulness. In an effort to determine why the sleeping cat's body does not respond to the messages being fired by the brain, the researcher removed a cluster of neurons from a sleeping cat's brain stem, the part of the brain that connects the cerebral cortex to the spinal cord. After he had done so, the still sleeping cat got up, pounced as if it were chasing a mouse, and arched its back.
Which of the following, if true, taken together with the information above best supports the conclusion that the sleeping cat was acting out its dreams?
A. The neurons that were removed from the brain stem normally serve to trigger the dream state of sleep and the rapid brain activity that accompanies it.
B. The cerebral cortex is able to receive and transmit sensory information even when the brain is in a sleeping state.
C. The neurons that were removed from the brain stem are normally responsible for transmitting messages from the cerebral cortex.
D. The neurons that were removed from the brain stem normally prevent messages fired by the cerebral cortex during sleep from being received by the spinal cord
E. The types of brain waves produced by the cerebral cortex during sleep have distinctly different properties from those produced during a wakeful state.