HELP PLEASE URGENT
The following is an incomplete paragraph proving that the opposite sides of parallelogram ABCD are congruent:
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According to the given information, AB || DC and BC || AD. Construct a diagonal from A to C with a straightedge. It is congruent to itself by the
Reflexive Property of Equality______.
Ву Angles BAC and DCA are congruent by the Alternate Interior Angles Theorem. Angles BCA and DAC are congruent by the Alternate Interior Theorem.
CPCTC, opposite sides AB and CD, as well as sides BC and DA, are congruent.
Which sentence accurately completes the proof?

( A )Triangles BCA and DAC are congruent according to the Angle-Angle-Side (AAS) Theorem.
( B )Triangles BCA and DAC are congruent according to the Angle-Side-Angle (ASA) Theorem.
( C / not correct ) Angles ABC and CDA are congruent according to a property of parallelograms (opposite angles are congruent).
( D ) Angles BAD and ADC, as well as angles DCB and CBA, are supplementary by the Same-Side Interior Angles Theorem.