Two light rays, initially in phase and with a wavelength of 500 nm, go through different paths by reflecting from the various mirrors shown in Figure. (Such a reflection does not itself produce a phase shift.)(a) What least value of distance d will put the rays exactly out of phase when they emerge from the region? (Ignore the slight tilt of the path for ray 2.)(b) Repeat the question assuming that the entire apparatus is immersed in a protein solution with an index of refraction of1.38.

d- -d- Ray 1 Ray 2