$A$ smooth sphere $A$ is moving on a frictionless horizontal plane with an angular speed $\omega$ and its center of mass has a linear velocity $v$. It undergoes an elastic collision with an identical sphere $B$,which is initially at rest. After the collision,their angular speeds are $\omega_A$ and $\omega_B$ respectively. Neglecting friction,which of the following is true?

• A
  $\omega_A < \omega_B$
• B
  $\omega_A = \omega_B$
• C
  $\omega_A = \omega$
• D
  $\omega = \omega_B$