Which diagram shows a pair of angle measure that proves lines $c$ and $d$ are parallel? d b .) a

Step 1 ：Check for corresponding angles, alternate interior angles, and alternate exterior angles in each diagram.

Step 2 ：Diagram a has congruent corresponding angles and alternate interior angles, which indicates that lines c and d are parallel in this diagram.

Step 3 ：\(\boxed{\text{Diagram a}}\) shows a pair of angle measures that prove lines c and d are parallel.