Answer
Option C is correct.
Side-Side-Side (SSS)
Step-by-step explanation
The key to proving that two triangles are similar or congruent is to prove that three of either side lengths or angles are congrunet, similar or the same.
For the figure given, we have already been told that
Side AB = Side CD
Side AD = Side CB
Since the two triangles share a similar side in BD, we can complete this by saying
Side BD = Side BD
Side AB = Side CD
Side AD = Side CB
Side BD = Side BD
So, three of the sides of the triangles are equal or congruent.
Hope this Helps!!!