Consider the following statements $A$ and $B$ and identify the correct answer.
$A$. In an elastic collision,if a body suffers a head-on collision with another of the same mass at rest,then the first body comes to rest while the other starts moving with the velocity of the first one.
$B$. Two bodies of equal mass suffering a head-on elastic collision merely exchange their velocities.

• A
  both $A$ and $B$ are true
• B
  both $A$ and $B$ are false
• C
  $A$ is true but $B$ is false
• D
  $A$ is false but $B$ is true