Two Extremely Flat Glass Plates,10

Multiple Choice

Two extremely flat glass plates,10.0 cm wide,touch at one end but are separated by a thin wire at the other end,forming a wedge.Light with a wavelength of 450 nm shines almost perpendicularly on the glass and forms fringes which are 1.80 mm apart.What is the diameter of the wire?

A) 25.0 µm
B) 17.5 µm
C) 20.0 µm
D) 12.5 µm
E) 10.0 µm