What are the applications of electromagnetic waves

-set the "atomic" clocks everywhere

-hear news & sports on AM radio

-low-band 2-way mobile radios ... fire, police, taxi, ambulance

-high-band 2-way mobile radios ... fire, police, taxi, ambulance

-over-the-air TV

-hear music on FM radio

-open the garage door while sitting in the car

-heat up leftover meatloaf in the 'microwave'

-cordless telephones in the house

-cellular telephones everywhere else

-all smartphone data, up and down, in and out  

-GPS, and everything that uses it

-control & communicate with GPS satellites, weather satellites, TV satellites, military and government satellites, lunar orbiters, Hubble Space Telescope, the International Space Station, all interplanetary space probes

-everything Bluetooth

-everything Laser

-everything Microwave

-use eyes to see things

-use Infrared to heat things

-use ultraviolet to get a tan

-X-rays for dental and medical applications

the answer would be a