Answer:
The correct option is;
SSS congruency theorem
Step-by-step explanation:
Given that opposite sides of a parallelogram are equal, whereby side AB is congruent to side CD and side BC is congruent to side DA and also that side AC is congruent to side CA, we have;
Triangle ABC with sides AB, BC, and AC is congruent to triangle CDA with corresponding sides CD, DA, and CA, by the Side-Side-Side (SSS) rule of congruency (two or more triangles that have all three sides of one triangle congruent to the three sides of the other triangle are congruent).