Since the mirror is in horizontal position, the image will just appear upside down.

In the figure, the bigger dot is on the left of the smaller and they have a gap between them, similarly in the mirror image it will appear as it is.

=> (C) & (D) are eliminated.

In the figure, one dot is in the front of half filled box, and the other is not, it will appear as it is in the mirror

=> (B) is also eliminated.

Ans - (A)