Degree of diabetic retinopathy depends on –: (A) Type of disease, (B) Duration of disease, (C) Severity of disease, (D) Retinal involvement
Answer is B. Risk factors for diabetic retinopathy 

Duration of disease after onset of puberty :- Most important risk factor.
Other :- Age of onset (before puberty), sex, poor glycemic control, hypertension, smoking, poor renal status, obesity, hyperlipidemia, pregnancy.