Ans: D. Albumin(Ref: Harrison 19/c p1715-1716)The most impoant diagnostic tests in pleural fluid specimen in a patient with suspected TB are GeneXpe (PCR) and ADA levels.Total protein levels and LDH levels are required to differentiate between transudative and exudative effusion according to Light's Criteria.So doing a pleural fluid albumin level separately will not be very useful.Total protein estimation should be done instead.