This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tumours of skin, Subject name: Dental
The range of UV light, which causes maximum skin damage, is: 
Select and explain. 
A. 760-800 nm, B. 360-400 nm, C. 290-320 nm, D. 240-290 nm
C: 290-320 nm
Answer: C: 290-320 nm 
Explanation: The biologically most active pa of the solar spectrum is UVB (290 -320 nm) since it is primarily responsible for the induction of inflammation, carcinogenesis and immunosuppression. UV-B - (wavelength 290 and 320 nm) most efficient in producing redness or erythema in human skin and thus is some- times known as the "sunburn spectrum." UV-A (wavelength 320 and 400 nm) is ~1000-fold less efficient in producing skin redness than is UV-B.