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 two year old child presents with persistent diarrhoea acidic stools and presence of one percent of reducing substance in the fresh stools. What is the most probable diagnosis ? 
Select and explain. 
A. Cystic fibrosis, B. Lactose intolerance, C. Rotavirus induced diarrhoea, D. Intestinal tuberculosis
B: Lactose intolerance
Answer: B: Lactose intolerance 
Explanation: None