In a double slit experiment the angular width of a fringe is found to be `0.2^(@)` on a screen placed I m away. The wavelength of light used in 600 nm. What will be the angular width of the fringe if the entire experimental apparatus is immersed in water ? Take refractive index of water to be `4//3`.
A. `0.2^(@)`
B. `0.27^(@)`
C. `0.3^(@)`
D. `0.15^(@)`
