What does it mean when an emission line of helium from a galaxy is shifted toward red?(1 point)

Responses

The galaxy is moving away from the viewer.
The galaxy contains a small percent of hydrogen.
The galaxy contains a large percent of hydrogen.
The galaxy is moving toward the viewer.

The galaxy is moving away from the viewer.

When an emission line of helium from a galaxy is shifted toward red, it means that the galaxy is moving away from the viewer.