Answer:
Option A
Explanation:
The statement makes sense since it's already explained that the galaxy is moving away from us and unlike option C which depicts that the galaxy is moving to us.
This statement makes sense. The redshift means that we see the galaxy moving away from us, so observers in that galaxy must also see us moving away from them—which means they see us redshifted as well
The momentum of the rolling ball will have less momentum than before the collision and the stationary ball will have more momentum after the collusion.