Final answer:
Without specific information about triangles CZB and CXA, we cannot determine which congruence postulate or theorem (SAS, ASA, AAS) justifies their congruence; SSA is not a valid rule for triangle congruence.
Step-by-step explanation:
To justify that triangles CZB and CXA are congruent, we would need to know more information about the triangles such as side lengths and angle measures in order to apply one of the congruence postulates or theorems. Without that specific information, it's not possible to choose between SAS (Side-Angle-Side), ASA (Angle-Side-Angle), SSA (Side-Side-Angle, which is not a valid congruence rule), or AAS (Angle-Angle-Side). For congruence, we typically need to know that either two sides and the included angle are congruent (SAS), two angles and the included side are congruent (ASA), or two angles and a non-included side are congruent (AAS). SSA does not generally prove congruence because it can lead to ambiguous cases where two triangles have the same two sides and a non-included angle but are not congruent.