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
Ring scotoma is seen in : 
Select and explain. 
A. Papilledema, B. Macular edema, C. CRAO, D. Retinitis pigmentosa
D: Retinitis pigmentosa
Answer: D: Retinitis pigmentosa 
Explanation: The hallmark symptoms of retinitis pigmentosa are night blindness (nyctalopia) and gradually progressive peripheral visual field loss as a result of increasing and coalescing ring scotomas. The most characteristic fundoscopic findings are attenuated retinal aerioles, waxy pale optic disk, mottling of the retinal pigment epithelium, and peripheral retinal pigment clumping, referred to as "bone-spicule formation. Ref : Fletcher E.C., Chong N., Augsburger J.J., Correa Z.M. (2011). Chapter 10. Retina. In P. Riordan-Eva, E.T. Cunningham, Jr. (Eds), Vaughan & Asbury's General Ophthalmology, 18e.