Final answer:
Benztropine is the treatment for acute dystonia and parkinsonism associated with antipsychotic extrapyramidal effects, as it can help restore neurotransmitter balance disrupted by dopamine antagonists like haloperidol.
Step-by-step explanation:
The treatment for acute dystonia and parkinsonism, which are potential side effects of antipsychotic drugs due to their dopamine antagonistic effects, is a) Benztropine. Benztropine is an anticholinergic drug which can alleviate symptoms by restoring the balance of neurotransmitters in the brain. Antipsychotics like haloperidol can lead to side effects by blocking dopamine receptors which can result in movement disorders due to disrupted neurotransmission in the basal nuclei, so using an anticholinergic agent like benztropine can help counter these movement disorders. It is important to note that while treating Parkinson's disease, increasing dopamine levels, for instance with L-DOPA, is a different therapeutic approach, as it supplies a dopamine precursor rather than directly counteracting the antipsychotic-induced side effects.