The following is not an atypical antipsychotic -: (A) Thioridazine, (B) Clozapine, (C) Olanzapine, (D) Risperidone
Answer is A. Antipsychotics (Neuroleptics) 

Antipsychotics are a group of psychoactive drugs commonly used to treat psychosis, e.g. Schizophrenia.
Antipsychotic drugs are divided into:

A) Typical antipsychotics (first-generation antipsychotics)

Phenothiazines - Chlorpromazine, Thioridazine, Trifluoperazine, Fluphenazine.
Thioxanthenes - Thiothixene, Flupenthixol.
Butyrophenones - Haloperidol, Trifluperidol, Penfluridol.
Other heterocyclics - Pimozide, Loxapine, Sulpiride

B) Atypical antipsychotics (second generation antipsychotics)

clozapine
Olanzapine
Risperidone
Questiapine
Aripiprazole
Ziprasidone