Iam stuck on this question. "viruses are considered to be which of the following? " (this is multiple choice)

Viruses are actually smaller than bacteria but they're not bacteria. So D is wrong.

Viruses don't grow and aren't made of cells, and despite being able to reproduce, they're not living. So C is correct.

As for the other two, I'm not entirely sure what they mean but C is the answer.

Viruses are non-living organisms. They attack host cells to live 

Greenhouse gases are the gases in the atmosphere that keep the air in the atmosphere.  It traps the sun's sunlight.  Since the heat is trapped in here, it would contribute to higher temperatures.