Answer

Correct Option: (ii) $2f_m$

Explanation

Amplitude Modulation: $s(t)=A_c[1+\mu m(t)]\cos\omega_c t$ with baseband $m(t)$ bandwidth $f_m$.

Spectrum: carrier at $f_c$ plus upper sideband $f_c+f_m$ and lower $f_c-f_m$.

Total transmission bandwidth:
$$B_T = (f_c+f_m)-(f_c-f_m)=2f_m$$

If $f_m=5$ kHz, $B=10$ kHz.

Other options: $f_m$ would be SSB, $f_c\pm f_m$ are sideband frequencies, not bandwidth.

Final Answer

AM bandwidth $=2f_m$ → Option (ii).