modulation is used to Select one:a. ensure information is transmitted over large distancesb. seperate different input signalsc. have practically possible height of antennad. all

Modulation is used for all of the above options.

a. It ensures information is transmitted over large distances: Modulation helps in transmitting signals over long distances by reducing the effect of noise and interference.

b. It separates different input signals: Modulation allows multiple signals to be transmitted simultaneously without interference by assigning each signal a different frequency or phase.

c. It allows for a practically possible height of antenna: The height of an antenna required for transmission is inversely proportional to the frequency of the signal. Modulation allows us to transmit signals at higher frequencies, thereby reducing the height of the antenna required.

d. So, all of the above statements are correct.