Which of the following four alternatives is not correct, We need modulation :-

Options

A. To increase the3 selectiveity
B. To reduce the time lag between transmission and reception of the information signal
C. To reduce the zise of antenna
D. To reduce the fractional hand waks that is the ratio of the signal hand width to the centre frequency.

Explanation

We know that low frequencies signals cannot be transimitted to long distances. That is why, the low frequency signal is superimposed on a high frequency signal by a process known as modulation. In modulation process, the speed of electromagnetic wave will not change. Due to it, we can reduce the time lag between trasmission and reception of the information signals.