This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Primary Angle-Closure Glaucoma, Subject name: Ophthalmology
Cause of red congested painful eye with mild dilated vertically oval pupil 
Select and explain. 
A. Acute congestive glaucoma, B. Anterior uveitis, C. Keratoconjunctivitis, D. Eale's disease
A: Acute congestive glaucoma
Answer: A: Acute congestive glaucoma 
Explanation: Ans. is 'a' ie. Acute congestive glaucomaDifferential diagnosis of common caused of Red eye* Acute conjunctivitisAcute anterior uveitisAcute congestive glaucomaCorneal trauma or infectionDischargeWateryNoneNoneWatery or purulentPainNoneModerateSevereMod to severeVisionNo effectSlightly blurredMarkedly blurredUsually blurredConjunctival injectionDiffuse; more towards fornicesMainly circumcornealMainly circumcornealMainly circumcornealCorneaClearUsually clearSteamyChanges in clarity related to causePupilNormalMiotic and unequalDilated , oval & fixedNormal or smallIOPNormalNormalElevatedNormalAC depthNDeepShallow