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: Microbiology
Regarding ETEC, true is - 
Select and explain. 
A. Invades submucosa, B. Most common in children of developing countries, C. Fomite borne and person to person, D. Not a common cause of traveller's diarrhea
B: Most common in children of developing countries
Answer: B: Most common in children of developing countries 
Explanation: None