Carol is right. The segment shared by these two triangles is congruent to itself by the Reflexive Property, and so these two triangles are congruent by ASA.
The triangles are mentioned as having a shared segment, which suggests that the side-angle-side (SAS) rule is applicable, not the angle-side-angle (ASA) rule. If the shared segment is a side and the corresponding angles are congruent, then Carol would be correct in stating that the triangles are congruent by the SAS rule.
Carol is right. The segment shared by these two triangles is congruent to itself by the Reflexive Property, and so these two triangles are congruent by ASA.