If a carrier wave $C(t) = A \sin \omega_c t$ is amplitude modulated by a modulating signal $m(t) = A \sin \omega_m t$,then the equation of the modulated signal $[C_m(t)]$ and its modulation index are respectively:

• A
  $C_m(t) = A(1 + \sin \omega_m t) \sin \omega_c t$ and $2$
• B
  $C_m(t) = A(1 + \sin \omega_m t) \sin \omega_m t$ and $1$
• C
  $C_m(t) = A(1 + \sin \omega_m t) \sin \omega_c t$ and $1$
• D
  $C_m(t) = A(1 + \sin \omega_c t) \sin \omega_m t$ and $2$