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
Which grade of ROP (Retinopathy of Prematurity) shows a ridge with retinal fibrovascular proliferation and neovasularisation? 
Select and explain. 
A. ROP 1, B. ROP 2, C. ROP 3, D. ROP 4
C: ROP 3
Answer: C: ROP 3 
Explanation: Retinopathy of Prematurity is a vasoproliferative retinopathy that affects premature and low-bih-weight infants. ROP stage 3 shows extra retinal fibrovascular proliferation at the ridge between normal and avascular retina. Stages of Retinopathy of Prematurity are: STAGE 1: Demarcation line dividing vascualr from avascular retina STAGE 2: Intraretinal ridge. Line of stage I aquires volume and rises above the surface retina to become a ridge. STAGE 3: Ridge with extra retinal fibrovascualr proliferation and neovascularization STAGE 4: Sub-retinal detachment including macula STAGE 5: Total retinal detachment