White light is passed through a double slit and interference pattern is observed on a screen 2.5 m away. The separation between the slits is 0.5 mm. The first violet and red fringes are formed 2.0 mm and 3.5 mm away from the central white fringe. Calculate the wavelengths of the violet and the red light.
a. 400 nm, 650 nm
b. 400 nm, 700 nm
c. 350 nm, 200 nm
d. 200 nm, 350 nm