Recall that SAS inplies Side, Angle in between, and other side.
So in the case given by the image:
we have the sides marked with a tick (Ab and BC) equal, We also have a common side (BD) which means it is equal for both, then we just need the angle in between these two sides to be equal. That is:
Angle ABD = Angle CBD
which is the second option in the listed possible answers.