This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology (General Propeies, DNA Viruses), Subject name: Microbiology
An HIV patient complains of visual disturbances. Fundal examination shows bilateral retinal exudates and perivascular haemorrhages. Which of the following viruses are most likely to be responsible for this retinitis- 
Select and explain. 
A. Herpes simplex, B. Varicella zoster, C. Cytomegalovirus, D. EBV
C: Cytomegalovirus
Answer: C: Cytomegalovirus 
Explanation: This is a typical feature of Cytomegalovirus (CMV) retinitis. Pizza pie appearance of fundus in CMV retinitis.(In HIV +ve patient, if CD4+ count is <50 cells/ microlitre) Herpes simplex- type 1 : conjuctivitis and corneal ulceration. Varicella zoster-corneal ulcer and zoster opthalmicus. EBV- not associated with retinitis.