**Core Concept**
Rhabdomyolysis is a serious syndrome characterized by the breakdown of skeletal muscle tissue, leading to the release of myoglobin into the bloodstream and subsequent myoglobinuria (presence of myoglobin in urine). This condition can be caused by various factors, including trauma, infections, and exposure to toxins.

**Why the Correct Answer is Right**
Multiple hornet stings can cause rhabdomyolysis due to the release of potent neurotoxins and histamine from the venom, which can lead to muscle necrosis and myoglobinuria. The venom from hornets can cause systemic effects, including muscle damage, renal failure, and cardiovascular instability. In severe cases, multiple hornet stings can result in significant morbidity and mortality.

**Why Each Wrong Option is Incorrect**
**Option A:** Viper bite is more commonly associated with local tissue damage, hemorrhage, and renal failure due to the coagulopathy caused by viper venom, but it is less likely to cause rhabdomyolysis.
**Option B:** Heat stroke is a form of heat-related illness that can cause rhabdomyolysis, but it is typically seen in the context of severe hyperthermia, often in patients with underlying medical conditions or those engaging in strenuous physical activity.
**Option C:** Malignant hyperthermia is a rare but life-threatening medical emergency caused by an abnormal reaction to certain anesthetics, leading to muscle rigidity, hyperthermia, and metabolic acidosis, but it is not typically associated with myoglobinuria.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize that rhabdomyolysis can be caused by a wide range of factors, including trauma, toxins, and infections, and that prompt recognition and treatment are crucial to prevent long-term kidney damage and other complications.

✓ Correct Answer: D. Multiple hornet stings