**Core Concept**
Placenta praevia is a condition where the placenta partially or completely covers the internal cervical os, posing a risk of hemorrhage during pregnancy, particularly in the third trimester. This condition is often associated with placental abruption and preterm labor.

**Why the Correct Answer is Right**
The correct answer is related to the management of placenta praevia. In cases where the placenta covers the internal cervical os, the primary goal is to maintain pregnancy until viability and avoid preterm labor. This is achieved through bed rest, close monitoring, and sometimes the use of corticosteroids to enhance fetal lung maturity. **Prostaglandin withdrawal and blood transfusions are often required**.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect because while pain is a symptom of placenta praevia, it is not the primary indicator of this condition. Pain is more commonly associated with placental abruption.

**Option B:** This statement is incorrect because vaginal bleeding is a hallmark symptom of placenta praevia, and it is often the presenting complaint. However, the bleeding can be painless and may be accompanied by other symptoms such as abdominal pain and uterine tenderness.

**Option C:** This statement is incorrect because while placenta praevia can be associated with a higher risk of preterm labor, it is not the primary cause. Other factors such as cervical incompetence and uterine anomalies also contribute to preterm labor.

**Clinical Pearl / High-Yield Fact**
In cases of suspected placenta praevia, a **transvaginal ultrasound** is often used to confirm the diagnosis. This imaging modality allows for a more accurate assessment of the placenta's location relative to the internal cervical os.

**Correct Answer:**.