In an $\text{FM}$ system, a carrier of $100\; \mathrm{MHz}$ is modulated by a sinusoidal signal of $5 \; \mathrm{kHz}$. The bandwidth by Carson's approximation is $1 \; \mathrm{MHz}$. If $y(t)=(\text {modulated waveform})^{3}$, then by using Carson's approximation, the bandwidth of $y(t)$ around $300 \; \mathrm{MHz}$ and the spacing of spectral components are, respectively.
- $3 \; \mathrm{MHz}, 5 \; \mathrm{kHz}$
- $1 \; \mathrm{MHz}, 15 \; \mathrm{kHz}$
- $3 \; \mathrm{MHz}, 15 \; \mathrm{kHz}$
- $1 \; \mathrm{MHz}, 5 \; \mathrm{kHz}$
