What are the frequency channels that GLONASS use for normal operation?

A)
i=-7 to +4
B)
i=-2 to +7
C)
i=-7 to +12
D)
i=+5 to +12

Correct Answer :   i=-7 to +4


Explanation : The GLONASS use i= -7 to +4 frequency channels for normal operation. This was done so that the signal does not interfere with the radio astronomy ground station which uses the same frequency band.