<prompt> All of the following are Lights criteria for exudative I pleural effusion:Pleural fluid protein to serum protein 0.5Pleural fluid LDH to serum LDH 0.6Pleural fluid LDH is 23 times the normal upper limit for serumPleural fluid ADA to Serum ADA 16  <response>: Answer is D Pleural fluid ADA and Serum ADA 16: Ratio of Pleural fluid ADA and Serum ADA 16 is not pa of Lights Criteria. Lights criteria, rely on a comparison of the chemistries in the pleural fluid to those in the blood, to establish the cause of the effusion as transudate or exudates. According to Lights criteria a pleural effusion is likely exudative if at least one of the following exists The ratio of pleural fluid protein to serum protein is greater than 0.5 The ratio of pleural fluid LDH and serum LDH is greater than 0.6 Pleural fluid LDH is greater than 0.6 or Y3 times the normal upper limit for serum. Note: Exudative Pleural Effusions meet at least one of the above criteria while transudative effusions meet None These criteria misidentify around 25 percent of transudates as exudates 