The Young's double-slit experiment is done in a medium of refractive index 4//3. A light of 600 nm wavelength is falling on the slits having 0.45 mm separation. The lower shift S_(2) is covered by a thin glass sheet of refractive index. 1.5. The interference pattern is observed on a screen placed 1.5 m from the slits as shown in Figure

a. Find the location of central maximum (bright fringe with zero path difference) on the y-axis.

Options

A. fringes will disappear
B. fringe width will increse
C. fringe width will decrease
D. there will be no change in fringe width.