Final answer:
Dantrolene is the muscle relaxant recommended for the treatment of NMS, acting to reduce severe muscle rigidity and metabolic demand. Atropine poisoning would be treated with a muscarinic agonist, whereas benzodiazepines are typically used for their anti-anxiety effects.
Step-by-step explanation:
The muscle relaxant recommended for the treatment of Neuroleptic Malignant Syndrome (NMS) is Dantrolene. Options A, B, and D (Bromocriptine, Trihexyphenidyl, Benztropine) are not typically used for this purpose. Dantrolene acts on the skeletal muscle, reducing muscle contractions by inhibiting calcium release from the sarcoplasmic reticulum. In the context of NMS, which can involve severe muscle rigidity, hyperpyrexia, and other life-threatening symptoms, Dantrolene is used to mitigate the muscle rigidity and reduce metabolic demand.
As for atropine poisoning, a muscarinic agonist would be the antidote choice, considering that atropine is an anticholinergic agent. For anti-anxiety effects, tranquilizers such as benzodiazepines (e.g., diazepam and Chlordiazepoxide) are often employed due to their sedative and hypnotic properties.