**Core Concept**
The question requires knowledge of a congenital anomaly that affects the gastrointestinal tract, leading to polyhydramnios, aspiration pneumonia, and feeding difficulties in the newborn. This condition is characterized by an abnormal communication between the esophagus and the trachea.

**Why the Correct Answer is Right**
The condition described is a form of tracheoesophageal fistula (TEF), specifically a type where the esophagus is not connected to the stomach but instead connects to the trachea. This leads to the accumulation of amniotic fluid in the uterus (polyhydramnios) due to the fetus's inability to swallow normally. The fetus also experiences difficulty feeding and may aspirate milk or formula into the lungs, leading to aspiration pneumonia. The excessive salivation and difficulty passing a nasogastric tube are also characteristic symptoms of TEF.

**Why Each Wrong Option is Incorrect**
**Option A:** Esophageal atresia without tracheoesophageal fistula would not typically present with polyhydramnios, as the fetus would still be unable to swallow amniotic fluid.
**Option B:** Congenital diaphragmatic hernia would present with respiratory distress and possibly gastrointestinal symptoms, but polyhydramnios and excessive salivation are not typical findings.
**Option C:** Esophageal stenosis would lead to difficulty feeding, but polyhydramnios and aspiration pneumonia are not characteristic symptoms.
**Option D:** Gastric volvulus would lead to abdominal pain and vomiting, but polyhydramnios and excessive salivation are not typical findings.

**Clinical Pearl / High-Yield Fact**
In cases of suspected tracheoesophageal fistula, a barium swallow study can help diagnose the condition by showing the abnormal communication between the esophagus and trachea.

**Correct Answer:** C. Esophageal atresia with tracheoesophageal fistula.