A 19-year-old male with no past psychiatric history presents to the emergency department with acute agitation, paranoia, and visual hallucinations. He is started on haloperidol 5 mg IM for behavioral control. On hospital day 1, nursing staff report he has become increasingly difficult to arouse, is drenched in sweat, and refuses to get out of bed due to severe muscle stiffness. Vital signs: temperature 39.8°C (103.6°F), heart rate 122/min, blood pressure 162/108 mmHg, respiratory rate 24/min. On examination, he demonstrates uniform rigidity of all extremities, including the neck. He is oriented only to self. Laboratory studies show elevated creatine kinase (CK) at 2,840 U/L (normal <200), and urinalysis shows myoglobinuria. Which of the following is the most appropriate immediate management?

1. A)Continue haloperidol and administer diphenhydramine to counteract extrapyramidal effects
2. B)Obtain CT head to rule out intracranial pathology, then reassess mental status
3. C)Immediately discontinue haloperidol and initiate supportive care with aggressive cooling and hydrationGABARITO
4. D)Switch from haloperidol to a second-generation antipsychotic such as olanzapine
5. E)Administer dantrolene and bromocriptine without discontinuing the antipsychotic medication