Archie drew a diagram to represent how light that casts a beam through a spaceship appears to an observer. each line in the diagram represents the beam of light as seen by the observer.

which labels best complete the diagram?

a. x: observer is on the ground, spaceship is at rest on the ground
y: observer is inside the spaceship, spaceship is traveling at a constant velocity
z: observer is on the ground, spaceship is traveling at a constant velocity
b. x: observer is on the ground, spaceship is traveling at a constant velocity
y: observer is inside the spaceship, spaceship is accelerating
z: observer is on the ground, spaceship is traveling at a constant velocity
c. x: observer is inside the spaceship, spaceship is accelerating
y: observer is inside the spaceship, spaceship is traveling at a constant velocity
z: observer is inside the spaceship, spaceship is at rest on the ground
d. x: observer is inside the spaceship, spaceship is traveling at a constant velocity
y: observer is inside the spaceship, spaceship is accelerating
z: observer is inside the spaceship, spaceship is at rest on the ground