<prompt> The nasopharynx is visualised in OPD by:PNS mirrorTongue depressorBoth PNS mirror and tongue depressorNone  <response>: c Both PNS postnasal space mirror and tongue depressorRef. Scott Brown, Vol 3; 98To examine nasopharynx or post nasal space in OPD, posterior rhinoscopy is done.Here the tongue is depressed using a tongue depressor and then the PNS mirror is passed behind the uvula. The glass surface of the PNS mirror is pre warmed so as to avoid mist formation, due to patients breath, during examination. 