We are asked to find out which lines are parallel.
As you can see from the given figure, the transversal OU cuts the two lines RP and SQ
The angles shown are called "Alternate Interior Angles"
According to the "Alternate Exterior Angles Theorem" when two parallel lines are cut by a transversal, the resulting alternate exterior angles are equal,
This means that the lines RP and SQ must be parallel.
Therefore, lines RP and SQ are parallel.
Alternate means on opposite sides and exterior means the outside angles.