Best range of UV light used for treatment of skin diseases: (A) 100 – 200 nm, (B) 200 – 400 nm, (C) 400 – 700 nm, (D) > 700 nm
Answer is B. UV light most commonly used in dermatology are UVB (290 - 320 mn), narrow band UVB (311 nm), and UVAi (360 - 380 nm).