The situation that describes opposite quantities that when combined would equal 0 is:
Eileen moves seven spaces forward, then she moves seven spaces back in a game.
This is because moving forward seven spaces and then moving back seven spaces cancels each other out, resulting in a net change of zero.
Another correct option is:
Sarah is charged a fee of $20 and withdraws $20.
This also results in a net change of zero, as the $20 charged (loss) and the $20 withdrawn (gain) balance each other out.
Both of these options describe situations where the quantities are opposite and sum up to zero.