Question

Which of these is the most likely use of an electromagnetic wave which has wavelength shorter than microwaves but longer than visible light?
Answer

heat food safely

take images of bones and teeth

transmit radio and cellular phone signals

detect the location of objects which emit heat

Answer 1

Microwaves are the waves that heat food safely.
XRays take images of bones and teeth - and have wavelengths much shorter than visible light
Radio signals are much slower than microwaves

*That leaves detect the location of objects that emit heat. Which are infrared waves, right between microwaves and visible light.