This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Social & Preventive Medicine
Mode of disposal of sewage ground water: 
Select and explain. 
A. Activated sludge process, B. Soakage pit, C. Oxidation pond, D. All of the above
A: Activated sludge process
Answer: A: Activated sludge process 
Explanation: It's aerobic oxidation process used as a secondary treatment Hea of this method is its Aeration tank