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 bottom left will be towards bottom right in the mirror image.

The triangle which is on the top right will be towards top left in the mirror image. The black part of the triangle which is towards bottom will be towards bottom in the mirror image.

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

Hence, the correct answer is Option B