A newborn baby had normal APGAR score at birth and developed excessive

A newborn baby had normal APGAR score at birth and developed excessive frothing and choking on attempted feeds. The investigation of choice is

1. Esophagoscopy 

2. Bronchoscopy 

3. MRI chest 

4. X-ray chest and abdomen with the red rubber catheter passed per orally into esophagus 

Ans 4