We can see that the figures B and B' have opposite orientations (exactly 180° difference).
Therefore, the first transformation that would help is a reflection over the y-axis.
This way, figure B would to quadrant II and will have the same orientation as B'.
Then, a second transformation that would make B go exactly to the position of B' is a translation of 6 units down.
(In order to find that we need exactly 6 units, we can compare the bottom point of B with the bottom point of B', and compare the y-coordinates)