A line is an undefined term because it

The three parallel arrows together rotate 45 degree anti ? clock wise and the arrow perpendicular to these three arrows rotates 135 degree clock wise. Arrow heads interchange position and colour.

All other figures can be rotated into each other.

From first figure to second figure the main design rotates through 45° clockwise and each line segment is doubled.

As we know that ,
The mirror image always be opposite the original image across the given line. Given image will become opposite to the given line AB.As shown in given below .

From first figure to second shaded part becomes white and vice-versa and the central design is rotated through 90°.

Increase of arc and faces in a single or one direction.

NA

On the basis of above given question figures , we can see that
In each subsequent figure the line segment rotates 90° clockwise and two arrow heads are added to both ends, one to each end.
Hence , required answer will be option B .As shown in above given answer figures .

From first unit to second unit the triangle rotates through 90° clockwise and moves to the side of square and a similar triangle appears on the opposite side.