Two Slits of Width a = 0

Multiple Choice

Two slits of width a = 0.020 mm are separated by a distance d = 0.05 mm and illuminated by light of wavelength λ = 500 nm. The number of bright fringes seen in the central maximum is

A) 2.5.
B) 3.
C) 4.
D) 5.
E) 6.