Theory is the correct answer. A scientific theory explains something about the natural world and can be tested via the scientific method to provide a reliable account of why something happens. If it has been suitably tested, it can be provisionally accepted by the scientific community.
What is it for tho. ?
The answer is; movement toward or away from Earth
Stars that move closer to the observer will be percieved as blue in the electromagnetic spectrum while starts moving away from the observer will appear red and orange. This is what is called the Doppler shift effect. This phenomenon is similar to the higher pitch of the siren of an ambulance approaching you and the low pitch of the siren when the ambulance passes you and is moving away from you.
The answer is D. I hope that helps you. also go help others on there answers so you can get points.
Answer:A great climate in another city
Explanation: