In A and in C, only the angles of one triangle are congruent to the corresponding angles of the other triangle. That proves similar triangles but not necessarily congruent triangles.
<em>Definition of congruent triangles:</em>
<em>Two triangle are congruent if all angles of one triangle are congruent to all corresponding angles of the other triangle and all sides of one triangle are congruent to all corresponding sides of the other triangle.</em>
