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

A vertical mirror is placed, so the object on the left will appear right in reverse position and vice-versa.

So the triangle at top left (facing left) will now face right at top right position (similar for other triangle), thus the first and last options will be eliminated.

Also, in the question figure, the direction of the two horizontal lines will be changed, hence third option is the right image.

=> Ans - (C)