The correct option is B AB=AC
In the triangles ΔADB and ΔADC,
AD is the common side.
BD = DC (Since D is the midpoint of BC)
For the triangles to be similar, the ratio of corresponding sides of ΔADB and ΔADC should be equal.
⇒ADAD=BDDC=ABAC⇒1=ABAC⇒AB=AC
Thus, if AB = AC, then both the triangles can be proved similar.