Interference fringes are observed on a screen by illuminating two thin slits 1 mm apart with a light source ($\lambda$ = 632.8 nm). The distance between the screen and the slits is 100 cm. If a bright fringe is observed on a screen at distance of 1.27 mm from the central bright fringe, then the path difference between the waves, which are reaching this point from the slits is close to :
(1) 2.87
(2) 2 nm
(3) 1.27 $\mu$m
(4) 2.05 $\mu$m
(1) 2.87
(2) 2 nm
(3) 1.27 $\mu$m
(4) 2.05 $\mu$m