<prompt> In a patient having HIV infections, oral ulcer is most commonly due to:CandidaCryptococcosisHistoplasmaTrichophyton  <response>: Ans. is a i.e., Candida Ref: Harrison, 18the, p. 1549, 1550; 17the, p. 1174 Amongst the given options, only Candida causes oral lesion in AIDS patient. 