At the point of intersection, the angles are equal because they are vertically opposite. This means that in both triangle, there are two congruent angles and a congruent sides. Recall,
if any two angles and the side included between the angles of one triangle are equivalent to the corresponding two angles and side included between the angles of the second triangle, then the two triangles are congruent by the (Angle side angle) ASA rule
Since the given triangles obey this rule, then the correct option is B