The correct options are
A Curved surface is spherical in shape.
B Surface is planar in shape.
D Refracting surface is convex in shape.
Equation of refraction of light at curved surfaces is given as:
μ2v−μ1u=μ2−μ1R
where, μ1 and μ2 is the refractive index of a two medium and R is the radius of curvature of the curved surface.
This equation are valid for any refracting surface for a small aperture.