**Core Concept**
Shoulder dystocia is a complication that can occur during vaginal delivery, characterized by the baby's shoulder becoming stuck behind the mother's pubic bone after the head has been delivered. This can lead to a range of serious consequences for both the mother and the baby.

**Why the Correct Answer is Right**
The correct answer is related to the consequences of shoulder dystocia. During shoulder dystocia, the brachial plexus nerves can be stretched or torn, leading to injury. The most common type of injury is the Erb's palsy, which affects the C5 and C6 nerve roots. This can result in weakness or paralysis of the arm, and in severe cases, can lead to long-term disability.

**Why Each Wrong Option is Incorrect**
* **Option A:** Erb's palsy is a common consequence of shoulder dystocia, so this option is incorrect.
* **Option B:** This option is incorrect because shoulder dystocia can lead to a range of serious consequences, including brachial plexus injury, but it is not a direct cause of maternal death.
* **Option C:** This option is incorrect because shoulder dystocia can lead to a range of complications, including brachial plexus injury, but it is not a direct cause of fetal death.

**Clinical Pearl / High-Yield Fact**
The McRoberts maneuver, which involves hyperflexing the mother's legs to widen the pelvis, is often used to try to resolve shoulder dystocia. However, this maneuver is not always effective, and other techniques, such as the Woods screw maneuver or the Rubin II maneuver, may be necessary.

**Correct Answer: D. Maternal death**