Final answer:
The side effect of neuroleptic drugs can be tardive dyskinesia, a disorder involving involuntary muscle movements due to interference with dopamine activity in the brain, similar to symptoms seen in Parkinson's disease.
Step-by-step explanation:
The potential side effect of neuroleptic drugs is B. tardive dyskinesia, a neurological disorder characterized by involuntary random movements of the facial muscles, tongue, and mouth, as well as extensive twitching of the neck, arms, and legs. Neuroleptic drugs, such as haloperidol, are known to affect dopamine activity in the brain. When these drugs interfere with dopamine in the extrapyramidal system, particularly in the basal nuclei, it can lead to disorders affecting motor control. Parkinson's disease, for comparison, is caused by the degeneration of neurons that release dopamine, leading to muscular symptoms that can sometimes show similarity to the side effects of neuroleptic drugs.