A message signal of frequency 100 MHz and peak voltage 100 V is used to execute amplitude modulation on a carrier wave of frequency 300 GHz and peak voltage 400 V. The modulation index and difference between the two side band frequencies are:\\
(1) $4 ; 2 \times 10 ^ { 8 } \mathrm {~Hz}$\\
(2) $0.25 ; 2 \times 10 ^ { 8 } \mathrm {~Hz}$\\
(3) $4 ; 1 \times 10 ^ { 8 } \mathrm {~Hz}$\\
(4) $0.25 ; 1 \times 10 ^ { 8 } \mathrm {~Hz}$