Work out how A is changed to give B, then choose the answer figure that is obtained from C by the same change.

B is the mirror image of A in an upright line: left and right are exchanged but nothing moves up or down. In the mirror image of C the flag stands on the right with its cloth pointing left, the square moves to the top-left and the dot to the bottom-left: (a). (b) flips top to bottom, (c) is a half turn and (d) also changes the shading.