Question

What does a red shift indicate about a galaxy?

Answer 1

The only cause we know of that could shift the spectrum of a source toward longer wavelengths isthe source moving away from us. That's how we interpret the red shift when we see it, and that's where the whole idea of the expanding universe comes from. But ... just like gravity and the Earth going around the sun ... it can't be proved, so it's "only a theory".

Answer 2

When a red shift happens that means a galaxy is moving away from us.
Therefore the answer is D.
Hoped I helped:D