Answer:
Option C.
Step-by-step explanation:
we know that
The Angle-Side-Angle (ASA) postulate states that if two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the triangles are congruent.
In this problem
The included side is the side CD and the angle ∠ACD and ∠ADC of triangle ACD are congruent with angle ∠BCD and ∠CDB of triangle BCD
therefore
Triangles ACD and BCD are congruent by ASA
