The First Angular Minima Location for a Single-Slit Diffraction Having $1 \mu \mathrm { m }$

Multiple Choice

The first angular minima location for a single-slit diffraction having slit width of $1 \mu \mathrm { m }$ and wavelength of 500 nm is

A) 10º.
B) 45º.
C) 20º.
D) 30º.