For the given figure, which one is the mirror line, `l_1 or l_2`?

For the given figure, which one is the mirror line, l1 or l2 ?

For the following figure which one is the mirror line?

For the following figures which one is the line l_1 or l_2 :

Which of the answer figure is exactly the mirror image of the given figure, which the mirror is held on the line AB ? Question Figure :

In the given figure, the mirror lines is given as dotted lines. The complete figure is of the form

In the given figure, the mirror line is given as dotted line. The complete figure is of the form