When an external force with angular frequency $\omega_d$ acts on a system of natural angular frequency $\omega$, the system oscillates with angular frequency $\omega_{\mathrm{d}}$. The condition for the amplitude of oscillations to be maximum is

• A

  $\omega_{\mathrm{d}}=2 \omega$
• Correct answer
  B

  $\omega_{\mathrm{d}}=\omega$
• C

  $\omega_d=\frac{\omega}{2}$
• D

  $\omega_{\mathrm{d}}=3 \omega$

Hence, the correct answer is option: 'B'.