Geometry

The answer is D. Point X and S are on the plane Q, so line XS is also on the plane Q.

1. First, understand the Plane - Line postulate:

The Plane - Line postulate states that if two points lie in a plane, then the line containing those two points lies in that plane.

2. Analyze each statement:

A.“Plane R and Q intersect at line WX.” This is an example of the postulate about the intersection of two planes, not the Plane - Line postulate.

B.“Plane R and Q intersect at line US.” This is also an example of the postulate about the intersection of two planes, not the Plane - Line postulate.