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
For a neonate at 48 hours of bih with a history of non-passage of meconium, next step in evaluation will be: 
Select and explain. 
A. Sweat chloride level, B. CFTR mutation analysis, C. Lower GI study, D. Manometry
C: Lower GI study
Answer: C: Lower GI study 
Explanation: Ans. c. Lower GI study