Which of the following is evidence that the evolution of disk galaxies can be greatly affected by their large scale environment?

Comparison of emissions from elliptical galaxies in x-ray and optical bands
Hydrogen gas deficiency in spiral galaxies near cluster cores
The abundance of irregular galaxies across clusters
We see less cluster evolution at larger redshifts

No, no no. Listen to the course work and learn.

Hydrogen gas deficiency in spiral galaxies near cluster cores!

The abundance of irregular galaxies across clusters

We see less cluster evolution at larger redshifts

Comparison of emissions from elliptical galaxies in x-ray and optical bands

The abundance of irregular galaxies across clusters

The answer is: Comparison of emissions from elliptical galaxies in x-ray and optical bands!