**Core Concept**
The patient's symptoms and radiographic findings are consistent with a condition involving the rupture of a hollow viscus leading to leakage of its contents into the thoracic cavity, causing a chemical pneumonitis and subsequent collapse.

**Why the Correct Answer is Right**
The likely diagnosis is a Boerhaave's syndrome, which is a rare but life-threatening condition characterized by a spontaneous rupture of the esophagus. This typically occurs in the setting of intense vomiting, retching, or heavy lifting, leading to a tear in the esophageal wall. The leakage of gastric contents into the mediastinum can cause a severe chemical pneumonitis, leading to a hydropneumothorax as seen on the chest X-ray. The esophageal rupture can also lead to a mediastinitis, which is an infection of the mediastinum.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it refers to a condition involving the rupture of the stomach, whereas the patient's symptoms and radiographic findings are more consistent with an esophageal rupture.

**Option B:** This option is incorrect because it refers to a condition involving the rupture of the duodenum, which is not consistent with the patient's symptoms and radiographic findings.

**Option C:** This option is incorrect because it refers to a condition involving the rupture of the esophagus, but it is a less severe condition than Boerhaave's syndrome, which typically involves a spontaneous rupture of the esophagus without any external trauma.

**Clinical Pearl / High-Yield Fact**
Boerhaave's syndrome is a medical emergency that requires prompt recognition and treatment. The patient should be immediately taken to the operating room for a thoracotomy and repair of the esophageal rupture. The mortality rate for Boerhaave's syndrome is high if not treated promptly.

**Correct Answer: C. Boerhaave's syndrome**