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
[{'content': 'Mode of disposal of sewage ground water: \nSelect and explain. \nA. Activated sludge process, B. Soakage pit, C. Oxidation pond, D. All of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: It's aerobic oxidation process used as a secondary treatment Hea of this method is its Aeration tank", 'role': 'assistant'}]