This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
Which of the following is earliest indicator of pathological gastroesophageal reflux in infants? 
Select and explain. 
A. Postprandial regugitation, B. Respiratory symptoms, C. Upper GI bleed, D. Stricture esophagus
B: Respiratory symptoms
Answer: B: Respiratory symptoms 
Explanation: Presence of respiratory symptoms point towards pathological GERD.
Stricture esophagus and upper GI bleed are complications due to severe GERD.