<prompt> In formol-ether concentration technique, which layer contains the parasites?EtherFecal debrisFormal waterSediment  <response>: 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. 