To determine if \( NO \) is a constructed copy of \( PQ \), Thuy needs to check if the length of segment \( NO \) is equal to the length of segment \( PQ \), and the segments must be anchored at the same point \( M \).
The correct response is:
She must measure the distance from point \( M \) to point \( Q \) using a compass and place the compass on point \( M \) to see if point \( O \) is the same distance.
This option is correct because it properly describes the process of using a compass to compare the lengths of segments \( NO \) and \( PQ \) while keeping point \( M \) fixed, which is necessary to show that \( NO \) is a copy of \( PQ \).