In Order to Produce Several Visible Interference Fringes from Two

Multiple Choice

In order to produce several visible interference fringes from two narrow slits using light of a single wavelength, the distance between the slits must be of the order

A) of a few tenths of the wavelength.
B) of a few wavelengths.
C) of a few tens wavelengths.
D) of a few hundreds wavelengths.
E) the distance does not matter.