What should the agile practitioner know about tracking velocity?

A team with an average velocity of 50 is twice as efficient as a team with an average velocity of 25.

A team with an average velocity of 50 is equally as efficient as a team with an average velocity of 25.

A team that consistently meets its planned velocity is more efficient than a team that consistently exceeds its planned velocity.

A team that consistently meets its planned velocity is less efficient than a team that constantly exceeds its planned velocity.