**Core Concept**
Preeclampsia is a pregnancy complication characterized by high blood pressure and signs of damage to another organ system, most often the liver and kidneys. The pathophysiology of preeclampsia involves endothelial dysfunction, abnormal angiogenesis, and increased oxidative stress.

**Why the Correct Answer is Right**
The treatment of preeclampsia involves managing blood pressure, preventing complications, and stabilizing the patient. **Methyldopa**, **Labetalol**, and **Nifedipine** are commonly used antihypertensive agents in preeclampsia due to their safety profile and efficacy. **Hydralazine** is also used in acute blood pressure management. **Sodium nitroprusside**, however, is not typically used in preeclampsia due to its potential for cyanide toxicity, especially in pregnant women.

**Why Each Wrong Option is Incorrect**
**Option A:** Methyldopa is actually used in preeclampsia; it's a centrally acting antihypertensive agent.
**Option B:** Labetalol is commonly used in preeclampsia; it's a mixed alpha and beta-blocker.
**Option C:** Nifedipine is also used in preeclampsia; it's a calcium channel blocker.
**Option D:** Hydralazine is used in preeclampsia; it's a vasodilator.

**Clinical Pearl / High-Yield Fact**
Remember that the treatment of preeclampsia focuses on stabilizing the patient and preventing complications, with a primary goal of delivering the baby when possible. Always consider the safety profile and potential side effects of antihypertensive agents in pregnant women.

**Correct Answer:** D. Sodium nitroprusside.