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

A horizontal mirror is placed, so the object on the top will appear at the bottom in reverse position and vice-versa.

So the semi circle at top side of square will now appear at bottom, thus the second and last options will be eliminated.

Also, in the question figure at bottom, triangle is facing upwards, hence it will appear at top facing downwards, hence third option is the right image.

=> Ans - (C)