Which expression is equivalent to (9m? + 5mn - 4n}) - (7m + 3mn + 6n})?

16m4 + 8m2n2 + 2n4

16m2 + 8mn + 2n2

2m2 + 8mn + 2n2

2m2 + 2mn - 10n2

The expression is equivalent to 2m2 + 2mn - 10n2.