A) (x, y) → (−x, −y); A′ is at (5, −1)
B) (x, y) → (−y, x); A′ is at (−1, −5)
C) (x, y) → ( y, −x); A′ is at (1, 5)
D) (x, y) → (x, −y); A′ is at (−5, −1)
