Given: Line segment N M is parallel to line segment P O. and Angle 1 is-congruent-to angle 3 Prove: Line segment N M is parallel to line segment N O.

4 lines are connected. Line segment L M connects to line segment M N to form angle 1. Line segment M N connects to line segment N O to form angle 2. Line segment N O connects to line segment O P to form angle 3.

A 2-column table has 5 rows. Column 1 is labeled statements with the entries line segment N M is parallel to line segment P O, angle 2 is-congruent-to angle 3, angle 1 is-congruent-to angle 3, angle 1 is-congruent-to angle 2, line segment L M is parallel to line segment N O.

What is the missing reason in the proof?

a. given
b. transitive property
c. alternate interior angles theorem
d. converse alternate interior angles theorem