<prompt> A 60 year old diabetic patient has an uneventful phacoemulsification with IOL implantation. He presented with pain, diminution of vision, redness, watering and a grayish yellow pupillary reflex on the third postoperative day. Examination revealed circumcorneal congestion, aqueous cells 4, hypopyon in the anterior chamber with posterior synechiae and retrolental flare. The most likely diagnosis is:Post-op endophthalmitisPost-op glaucomaPost-op keratitisPost-op cystitis  <response>: A i.e. Post-op endophthalmitis 