Two plane mirror `M_(1) "and" M_(2)` are inclined to each other at `70^(@)`. A ray incident on the mirror `M_(1)` at an angle `theta` fallls on `M_(2)` and is then reflected parallel to `M_(1)` for

Options

A. `theta= 45^(@)`
B. `theta= 50^(@)`
C. `theta= 55^(@)`
D. `theta=60^(@)`

Answer

B

Explanation

`90^(@) - theta = 180^(@)- 70^(@)- 70^(@) implies theta = - 50^(@)`