the presence of dark matter red shift of light from distant galaxies constant speed of light from every perspective emission of high-energy gamma rays by distant objects
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which is evidence that the universe is expanding?
Possibilities:
- the presence of dark matter
- red shift of light from distant galaxies
- constant speed of light from every perspective
- emission of high-energy gamma rays by distant objects

red shift of light from distant galaxies