Which shows the pre-image of quadrilateral W'X'Y'Z' before the figure was rotated according to the rule (x, y) → (-x, -y)?

Right ∆abc has coordinates a(-7, 3), b( -7, 10), and c(-1, 3). the triangle is reflected over the x - axis and then reflected again over the y - axis to create ∆a'b'c'. which are the coordinates of vertex a'?