**Core Concept**
Clozapine therapy is associated with a risk of agranulocytosis, a potentially life-threatening decrease in white blood cell (WBC) count. Regular monitoring of WBC count is essential to prevent this complication.

**Why the Correct Answer is Right**
The correct answer is based on the guidelines for monitoring WBC count in patients on clozapine therapy. Clozapine-induced agranulocytosis is a dose-related side effect, and regular monitoring helps identify patients at risk. The WBC count should be checked at least once a week for the first six months, and then once a week if the count is less than 1,500 cells/μL. If the WBC count falls below 1,000 cells/μL, clozapine therapy should be stopped.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is too low. Stopping clozapine therapy is not necessary until the WBC count falls below a certain threshold.
**Option B:** This option is incorrect because it is too high. Clozapine therapy should be stopped when the WBC count falls below a lower threshold.
**Option C:** This option is incorrect because it does not provide a clear threshold for stopping clozapine therapy.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that clozapine-induced agranulocytosis is a medical emergency, and prompt action is needed to prevent serious consequences. Regular monitoring of WBC count is crucial to prevent this complication.

**Correct Answer: B. 350 cells/μL**