56. A medical blue light therapy laser treatment pen emits a blue light with wavelength of 415 nm in the visible light. The index ofrefraction for air and cornea is 1.00 and 1.34, respectively. What is the wavelength of this blue light when that enters into corneafrom air? (Speed of light in vacuum is 3 × 108 m/s)
(A) 185 nm
(B) 310 nm
(C) 486 nm
(D) 556 nm
(E) 693 nm