Correct Answer:

Solution : As per the mirror image properties, closer things appear close to the mirror in the reflection.
Here, according to the information provided, the mirror is placed on the bottom side of the figure (on line AB). So, the top side of the reflected image will appear as the bottom side, and the bottom side will appear as the top side. However, the left and right sides of the reflected image will remain the same.

Thus, the correct mirror image of the given figure will be –

Hence, the fourth option is correct.