If the Function Is One-To-One, Find Its Inverse

If the function is one-to-one, find its inverse. If not, write "not one-to-one."
-{(3, -5) , (5, -3) , (9, 2) , (-9, -2) } 49)

A) {(-2, 9) , (9, 5) , (-5, 3) , (2, -9) }
B) {(-5, 3) , (-3, 5) , (2, 9) , (-2, -9) }
C) not one-to-one
D) {(-2, 9) , (-3, 5) , (-5, 5) , (2, -9) }