This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Uveal Tract, Subject name: Ophthalmology
[{'content': 'Which of the following protozoan affects the eye? \nSelect and explain. \nA. E. histolytica, B. E. coli, C. Giardia lambia, D. Toxoplasma', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) ToxoplasmaRef: Yanoff 3/e, Chapter 7.12 Ocular; Toxoplasmosis; Harrison 18/e, p. 1724Toxoplasmosis is the most common cause of posterior uveitis and accounts for approximately 90% of focal necrotizing retinitis.', 'role': 'assistant'}]