A converging lens of focal length `f_(1)` is placed in front of and coaxially with a convex mirror of focal length `f_(2)`. Their separation is d. A parallel beam of light incident on the lens returns as a parallel beam from the arrangement, Then,

Options

A. The beam diameters of the incident and reflected beams must be the same
B. d = `|f_(1)|-2 |f_(2)|`
C. d= `|f_(1)|- |f_(2)|`
D. If the entire arrangement is immersed in water , the conditions will remain unaltered

Answer

A

Explanation

d = `|f_(1)| - 2 |f_(2)|`