Okay, let's tackle this question about the most common cause of maternal mortality. The user provided the question with options A to D but didn't list the options themselves. Hmm, that's a bit tricky, but maybe I can infer the likely options based on standard medical knowledge.

First, I need to recall the core concept. Maternal mortality refers to deaths during pregnancy or within 42 days of termination. The leading causes typically include postpartum hemorrhage, hypertensive disorders like preeclampsia/eclampsia, sepsis, and obstructed labor. But which is the most common?

In many low-resource settings, postpartum hemorrhage is the top cause. However, in higher-income countries, it might be hypertensive disorders. Wait, but globally, the WHO data might show postpartum hemorrhage as the leading cause. Let me confirm. Yes, according to WHO, postpartum hemorrhage is the leading cause of maternal mortality worldwide, especially in regions with limited access to emergency obstetric care.

So the correct answer is likely postpartum hemorrhage. The options might be A. Postpartum hemorrhage, B. Preeclampsia, etc. But since the user didn't list the options, I need to structure the explanation around this.

For the Core Concept, I'll state that postpartum hemorrhage is the most common cause. Then explain why: it's due to uterine atony, trauma, or retained placenta. The clinical pearl should mention the importance of timely intervention with uterotonic drugs like oxytocin.

Now, for the incorrect options. If the options include preeclampsia, sepsis, or obstructed labor, I need to explain why they're less common. Preeclampsia is a leading cause but not the most common globally. Sepsis and obstructed labor are significant but less frequent than postpartum hemorrhage.

I should make sure the explanation is concise, uses correct terminology, and fits within the character limit. Also, structure each section as per the user's instructions. Let me check the character count to ensure it's under 2,500.

**Core Concept**
Maternal mortality is defined as death during pregnancy or within 42 days of termination, excluding accidental or incidental causes. The leading global cause is **postpartum hemorrhage (PPH)**, primarily due to uterine atony, followed by hypertensive disorders like preeclampsia/eclampsia and sepsis.

**Why the Correct Answer is Right**
Postpartum hemorrhage accounts for **~27% of maternal deaths globally**, especially in low-resource settings. It results from uterine atony (failure of the uterus to contract after delivery), trauma, or retained placental tissue. Uterine atony is often managed with uterotonic agents (e.g., oxytocin), but delays in diagnosis or treatment can lead to hypovolemic shock and death.

**Why Each Wrong Option is Incorrect**
**Option A:** Preeclampsia/eclampsia is a major cause but ranks second after PPH. It involves hypertension and multiorgan dysfunction but is less frequent than PPH.
**Option B:** Sepsis contributes to maternal mortality but is less common than PPH, often due to delayed access to antibiotics or poor infection control

✓ Correct Answer: A. Post paum hemorrhage