When it has a magnetic field
You've got some UHF radio waves at the long end of that range. But most of the range consists of <em>microwaves</em>.
For example: In the US, the "microwave oven" kitchen appliance cooks with radiation at a wavelength of about 12.2 cm .
"The path difference between the two waves should be one-quarter of a wavelength" is the statement among the choices given in the question that describes the <span>path difference between the two waves. The correct option among all the options that are given in the question is the fifth statement or the penultimate statement.</span>