If the image of a stone placed infront of a mirror is seen by the observer 1 at position C, then where will the observer 2 see the image?
At 'C'
The image distance is always equal to the object distance for a plane mirror. So, the position of the image with respect to the mirror depends only on where the object is placed and not on the observer. Hence, the observer 2 or any other observer for that matter, will see the stone at C and at no other position.