To determine if segment \( \overline{NO} \) is a copy of \( \overline{PQ} \), Thuy must verify that the lengths of the segments are equal. Specifically, she should measure the distance from point \( O \) to point \( Q \) and see if, when that distance is transferred to point \( P \), it lands at point \( N \).
The correct option based on this reasoning would be:
She must measure the distance from point O to point Q using a compass and place the compass on point P to see if point N is the same distance.