Correct option is D
f is the focal length
- Concave mirror:A Concave mirror is a spherical mirror with the reflective surface curved inward ( like the inside of a sphere). It is also concave mirror.
- Focus of a concave mirror: The focus of a concave mirror of trr is a point on the principle axis where parallel rays of light, after reflection from the mirror, converge.
- Center of Curvature of a Concave mirror:The center of curvature (C) is the center of the sphere of which the concave mirror is a part. It is a position on the principal axis located at a equal to the radius of curvature (R) from the pole (P).

The angle of minimum deviation of that prism is _________.