**Core Concept**
Clozapine is an atypical antipsychotic medication used primarily for treatment-resistant schizophrenia. Its unique pharmacological profile makes it a valuable option for patients who have not responded to other antipsychotics. Clozapine's efficacy is thought to be related to its ability to modulate various neurotransmitter systems, including dopamine, serotonin, and norepinephrine.

**Why the Correct Answer is Right**
The adult dose of Clozapine typically ranges from 300 to 900 mg per day, with a recommended starting dose of 25-50 mg per day. The dose is gradually increased as needed and tolerated, with a maximum recommended dose of 900 mg per day. Clozapine's pharmacokinetics are characterized by a large volume of distribution and extensive protein binding, which may contribute to its long half-life and potential for drug interactions.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not provide a specific dose range for Clozapine.
* **Option B:** This option is incorrect because it is lower than the recommended starting dose of Clozapine.
* **Option C:** This option is incorrect because it is higher than the maximum recommended dose of Clozapine.

**Clinical Pearl / High-Yield Fact**
It is essential to monitor patients taking Clozapine for agranulocytosis, a potentially life-threatening side effect characterized by a significant reduction in white blood cell count. Regular blood counts should be performed every week for the first six months and every two weeks thereafter.

**Correct Answer: D. 900 mg**