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: Dental
Improved Drinking water source protect from 
Select and explain. 
A. Fecal matter, B. Teratogenic, C. Inorganic, D. Not Recalled
A: Fecal matter
Answer: A: Fecal matter 
Explanation: None