Please be more specific because they all transmit signals but the most common one is the radio wave because it transmits cellphone , televition and radio signals
Radio waves are of longest wavelength and with smallest frequency
So here we can say that the wavelength range is very large and frequency range is less so here these waves are safe to use as these are not dangerous to us.
Since all electromagnetic waves consist of energy of different range depends on the frequency of the waves so in order to use them for communication purpose we have to use those waves which will have less energy so that these waves will remain useful for us.
So here correct answer for communication purpose will be
To obtain a shutter speed of 1/1000 s to avoid any blur motion the f-number should be changed to F4.0 because the light intensity goes up by a factor of 2 when the f-number is decreased by the square root of 2.
