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
Traveller's diarrhoea is caused by- 
Select and explain. 
A. Shigella, B. E. Coli, C. E. histolytica, D. Giardiasis
B: E. Coli
Answer: B: E. Coli 
Explanation: None