In the context of impulse and momentum, momentum is defined as $p=mv$. If an object's momentum changes, what quantity (or quantities) could have changed?

• A. Only the mass $m$ can change.
• B. Either the mass $m$, the velocity $v$, or both can change.
• C. Only the velocity $v$ can change.
• D. Neither $m$ nor $v$ can change; only time can change.

Answer: (B)