To find the correct mirror image when the mirror is placed at line MN, we need to consider the symmetry and orientation of the elements in the given figure.

Here are the steps to determine the correct mirror image:

1. In a mirror image, the left side of the object appears on the right side and vice versa.
2. The character orientation is reversed horizontally. For instance, the letters and numbers will flip as if they are viewed from behind.
3. Starting from the rightmost side, examine each character and determine how it would appear in a mirror placed on the right side.

Applying these principles to the given figure:

We will reverse each character horizontally:

• The string "mnuw496IL" will look like "LI694wnum" when viewed in the mirror.

Upon examining the given options, the mirror image must match "LI694wnum". The correct answer is:

This option reflects all the characters in the correct mirror-oriented manner.

Conclusion: The correct mirror image is represented by option 2.