Question

If we move mirror M2 in a Michelson interferometer and the fringe pattern shifts by 1.00 fringe, how far did we move the mirror?
a) 0 Wavelength
b) 0.25 Wavelength
c) 0.50 Wavelength
d) 0.75Wavelength
e) 1.00 Wavelength
f) 2.00 wavelengths