You need an even number of reflections to get the original figure, leaving only A and D as potentially viable choices.
The reflection across the x-axis makes the tranformation (x, y) ⇒ (x, -y). The reflection across the line y=x makse the transformation (x, y) ⇒ (y, x). The two pairs of transformations of A give (x, y) ⇒ (x, -y) ⇒ (-y, x) ⇒ (-y, -x) ⇒ (-x, -y) . . . . . not the original
The reflection across the y-axis makes the transformation (x, y) ⇒ (-x, y). The two pairs of transformations of D give (x, y) ⇒ (y, x) ⇒ (y, -x) ⇒ (-x, y) ⇒ (x, y) . . . . . . the original point