This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'In formol-ether concentration technique, which layer contains the parasites? \nSelect and explain. \nA. Ether, B. Fecal debris, C. Formal water, D. Sediment', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Concentration techniques include:Sedimentation techniquesFormol-ether concentration techniqueFormol detergent concentration techniqueFloatation techniquesSodium chloride floatation techniquesZinc sulphate floatation techniqueSugar floatation techniqueFormol-ether concentration technique is overall best sedimentation technique. It is rapid and gives good results. The figure shown in reference mentioned clearly shows sediment-containing parasites.', 'role': 'assistant'}]