Answer the following question given this paragraph: 

We see many objects out in space that emit light. We see other objects that emit other types of electromagnetic radiation. The matter we can see is contained in stars. The stars are contained in galaxies. Scientists think that stars and galaxies make up only a small part of the matter in the Universe. The rest of the matter is called dark matter .


Q: What is the area of our universe that isn't stars and galaxies called?

 Choices:

- nebula

- solar systems

- galaxies

- dark matter

A:
dark matter
