**Core Concept**
External cephalic version (ECV) is a procedure where a healthcare provider manually attempts to turn a breech baby to a head-down position before birth. It involves a combination of abdominal and uterine massage, along with gentle manipulation of the fetus. The goal of ECV is to prevent complications associated with breech presentation, such as umbilical cord prolapse, obstructed labor, and fetal distress.

**Why the Correct Answer is Right**
The correct answer is an exception to the contraindications for ECV. ECV is generally contraindicated in cases where the fetus is not viable, or where the mother has a multiple pregnancy, a previous uterine surgery, or a previous failed ECV. However, there are certain situations where ECV can still be attempted despite these contraindications, such as in cases of placenta previa or a history of uterine rupture. The key is to weigh the risks and benefits of attempting ECV in these situations.

**Why Each Wrong Option is Incorrect**
* **Option A:** A history of previous uterine surgery is a contraindication for ECV because it increases the risk of uterine rupture during the procedure.
* **Option B:** A previous failed ECV is also a contraindication because it may indicate a higher risk of complications during the procedure.
* **Option C:** Placenta previa is not a contraindication for ECV, as it can actually be a relative indication for the procedure to avoid the risks associated with vaginal delivery.

**Clinical Pearl / High-Yield Fact**
It's essential for healthcare providers to carefully evaluate each patient's situation before attempting ECV, taking into account factors such as fetal viability, maternal medical history, and the risks associated with vaginal delivery.

**Correct Answer:** C.