select the correct answer from each drop-down menu.
in the figure, ac and bd bisect each other. complete the statements to prove that quadrilateral abcd is a parallelogram.

reason options for 3rd statement:
•alternate interior angles theorem
•vertical angles theorem
•alternate exterior angles theorem

reason options for 9th statement:
•converse of alternate exterior angles theorem
•converse of alternate interior angles theorem
•converse of corresponding angles theorem
•converse of exterior angle theorem