In Young's double slit experiment `S_(1)` and `S_(2)` are two slits. Films of thickness `t_(1)` and `t_(2)` and refractive indices `mu_(1)` and `mu_(2)` are placed in front of `S_(1)` and `S_(2)` respectively. If `mu_(1)t_(1) = mu_(2)t_(2)`, then the central maximum will :

Options

A. not shift
B. shift towards `S_(2)` irrespective of amounts of `t_(1)" and "t_(2)`
C. shift towards `S_(2)` irrespective of amounts of `t_(1)" and "t_(2)`
D. shift towards `S_(1)" if "t_(2) gt t_(1)` and towards `S_(2)" if "t_(2) lt t_(1)`.

Answer

D