A Michelson Interferometer Is Set Up for Microwaves

Multiple Choice

A Michelson interferometer is set up for microwaves. Initially the reflectors are placed so the detector reads a maximum. When one of the reflectors is moved 12 cm, the reading goes from a maximum to a minimum and back to maximum six times. What is the wavelength of the microwaves?

A) 0.5 cm
B) 4 cm
C) 1 cm
D) 2 cm