This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Cotton wool spots are commonly seen in –a) AIDSb) DMc) Hypertensiond) CMV 
Select and explain. 
A. ab, B. bc, C. acd, D. abc
D: abc
Answer: D: abc 
Explanation: Causes of soft exudates (cotton wool spots)

All types of severe hypertension (hypertensive retinopathy) including renal disease, Toxemia of pregnancy.
Diabetic retinopathy
Collagen vascular disorders :- SLE, PAN, systemic sclerosis, scleroderma, wegener granulomatosis.
Infections :- AIDS, septic retinitis (including SABE), rarely CMV retinitis in AIDS.
Microembolization :- IV drug abuse, Post cardiac surgery, Fat embolism or Purtscher retinopathy.
Other Eale's disease, Adults anemia (Hb < 6.6-8.0 g/d1), Pseudoxanthoma elasticum, Neoplasia (Leukemia, Hodgkin's disease), Sickle cell retinopathy, radiation retinopathy
Now you must be thinking, why have I not included CMV in the answer? Read question carefully, examiner is asking about common causes. In CMV retinitis, cotton wool spots occur rarely.