JEE Main 2019 Physics question

The eye can be regarded as a single refracting surface. The radius of curvature of this surface is equal to that of cornea (7.8 mm). This surface separates two media of refractive indices 1 and 1.34. Calculate the distance from the refracting surface at which a parallel beam of light will come to focus:

• (A)2 cm
• (B)3.1 cmCorrect
• (C)4.0 cm
• (D)1 cm