This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neonatal Resuscitation, Subject name: Pediatrics
What is the single most effective step in resuscitation of babies who fail to breathe at bih? 
Select and explain. 
A. Suction of airways, B. Tactile stimulation, C. Positive pressure ventilation, D. Chest compressions
C: Positive pressure ventilation
Answer: C: Positive pressure ventilation 
Explanation: Positive pressure ventilation is the single most effective step in the resuscitation of neonates who fail to breathe at bih. Device used for PPV- 'Ambu bag'