A transparent film of refractive index, 2.0 is coated on a glass slab of refractive index, 1.45. What is the minimum thickness of transparent film to be

A transparent film of refractive index 2.0 is coated on a glass slab of refractive index, 1.45. What is the minimum thickness of transparent film to be coated for the maximum transmission of Green light of wavelength 550 nm. [Assume that the light is incident nearly perpendicular to the glass surface.] 

(1) 94.8 nm 

(2) 68.7 nm 

(3) 137.5 nm 

(4) 275 nm                   (JEE-2025)