Do you have to salute a cadet?

Answer 1

The salute is the greeting among the military. The junior rank/enlisted is required to render the salute first and hold it until the officer drops his salute. Cadets have not taken the oath of office and have not been commissioned. They may be saluted by enlisted. An officer would return a cadet's salute.

It is not be a requirement for an enlisted man to render a salute to a cadet but it may not be career enhancing to give a cadet the brush-off when presented with the opportunity to render the greeting.