If a boy moves with a speed $v$ towards a mirror, the image, to him, will appear to move with a speed:

The correct option is A $2v$ towards the mirror
If a boy moves with a speed $v$ towards (or away) from a mirror, the image will also move with a speed $v$ towards the mirror with respect to the mirror.

So, relative speed of the image, towards the mirror, with respect to the boy, will be $[v-(-v\left)\right]=2v$