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
A 2-year-old child, fed on milk diet, presents with persistent diarrhea, acidic stools (pH of stools less than 5.5) on two separate occassions and presence of 1% of reducing substances in the fresh stools. What is the most probable diagnosis: September 2012 
Select and explain. 
A. Cystic fibrosis, B. Lactose intolerance, C. Rotavirus induced diarrhoea, D. Intestinal tuberculosis
B: Lactose intolerance
Answer: B: Lactose intolerance 
Explanation: Ans. B i.e. Lactose intolerance