A term newborn presents with frothing, excessive drooling of saliva, coughing of saliva. There was history of polyhydramnios in antenatal period. There is difficulty in passing a  nasogastric tube. What is the probable diagnosis?
Diaphragmatic hernia
Choanal atresia
Gastroschisis
Tracheo-esophageal fistula
Tracheo-esophageal fistula :

Newborn presents with frothing, excessive salivation.
Associated with polyhydramnios in antenatal period.
Nasogastric tube is inserted and inability to pass it confirms the diagnosis of TEF.