If a mirror is placed on the line MN, then which of the answer figures is the right image of the given figure?

When the mirror is placed on the line MN,

The facing of the figure to the left and right direction changes to the opposite direction in the mirror image(left facing changes to right and vice versa). There won't be change in top and bottom direction.

The circle which is on the top left will be towards top right in the mirror image.

The dark triangle which is on the right will be towards left in the mirror image.

$$\therefore\ $$The mirror image of the given figure is

Hence, the correct answer is Option D