Two plane mirrors kept parallel to each other as shown in the diagram. A point object is placed at point A. How many images will get formed in the given situation :

The correct option is A Two

Image formed in $M_1$
We see that the light ray reflected from $M_1$,is not going to hit $M_2$.( Except the ray falling normal to the mirror), but since one ray is not sufficient to make an image hence the image of $I_1$ will not get formed in $M_2$.
Image formed in $M_2$



We see that the light ray reflected from $M_2$,is not going to hit $M_1$.( Except the ray falling normal to the mirror), but since one ray is not sufficient to make an image hence the image of $I_2$ will not get formed in $M_1$.
So, finally, the ray reflected from any one of the mirrors is not "going to hit" the other mirror except one ray (which is the ray along the normal). We know one ray only is not sufficient to form an image.
So, $I_1$, will not form any image in $M_2$ and $I_2$ will ot form any image in $M_1$.