**Core Concept**
Clozapine is an atypical antipsychotic medication primarily used to treat schizophrenia, particularly in patients who have not responded to other treatments. It has a unique pharmacological profile with a high affinity for serotonin and dopamine receptors, which contributes to its efficacy and side effect profile.

**Why the Correct Answer is Right**
Clozapine is known to cause several side effects, including agranulocytosis, a potentially life-threatening decrease in white blood cell count. It also causes weight gain, sedation, and orthostatic hypotension due to its effects on the serotonin and dopamine systems. Clozapine's unique pharmacology also leads to anticholinergic side effects such as dry mouth, constipation, and blurred vision.

**Why Each Wrong Option is Incorrect**
* **Option A:** is a correct side effect of clozapine, so it is not the answer.
* **Option B:** is also a known side effect of clozapine, so it is not the answer.
* **Option C:** is another correct side effect of clozapine, so it is not the answer.

**Clinical Pearl / High-Yield Fact**
Clozapine is the only atypical antipsychotic that requires regular monitoring of white blood cell counts to prevent agranulocytosis. This is a critical aspect of its management and requires close collaboration between the prescribing physician and the patient.

**Correct Answer:** D.