Which of the following must be true for the parallelogram shown below?

Answer:
DAB = BCD
Step-by-step explanation:
DAC = BAC = 90 degrees and DAB = ABC = 90 degrees don't work because they're both equilateral triangles and don't have a right angle that would equal 90. DAB = ABC are clearly not congruent so the answer is DAB = BCD. Also DAB = BCD share the same midsection line.