This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacotherapy in psychiatry, Subject name: Anatomy
drug used in the management of treatment resistant schizophrenia is 
Select and explain. 
A. clozapine, B. olanzapine, C. flupenthixol, D. haloperissol
A: clozapine
Answer: A: clozapine 
Explanation: CLOZAPINE * Impoance * First SGA * TREATMENT FOR TREATMENT RESISTANT SCHIZOPHRENIA * TOC for TD * Anti suicidal * Psychosis in parkinsonian patients Ref.kaplon and sadock, synopsis of psychiatry, 11 th dition, 935