Netball averages

This task is about what is needed to work out an average.

In its last game, a netball team scored 45 goals.

Up to that time it had an average of 25 goals per game.

What else do you need to know to find out the average score after the final game?

(A) Nothing.
(B) The number of players in a netball team.
(C) The number of times they scored more than 25 goals.
(D) The number of games they played altogether.
(E) The number of times they scored fewer than 25 goals.