Answer:
I believe the answer is D
Explanation:
I did it by eliminating all other options
A cant be true because with a 90 degree rotation RS is going to be perpendicular to R'S', not parallel.
B can't be true because SP is a straight line and R'S' like RS wont be (rotation doesn't change the fact that it isn't a completely straight line.
Now, rotation doesn't affect the degree of an angle. so...
C can't be true because 60 degrees isnt just going to change to 80 degrees out of nowhere
but D can be true because of this rule.
I hope this helps!