Observe the figures and find a mirror image of the same from the alternatives given. Imagine that MN is a mirror.
A horizontal mirror is placed, so the object on the top will appear at the bottom in reverse position and vice-versa.
So the two triangles at the top will now appear at the bottom, thus the third option will be eliminated. Also, the mouth is at the bottom right side of face, which will move to top right side, hence second option is also eliminated.
Now among the remaining options, first image correctly resembles the mirror image in the question figure, hence first option is the right image.