How Does the Study of Quasars Reveal Information About the History

Multiple Choice

How does the study of quasars reveal information about the history of the universe?

A) Quasars are very distant, so we see them as they were in the past.
B) Quasars contain stars of all ages.
C) Quasars typically act as host galaxies for gravitational lensing.
D) Quasars generate their energy in very small volumes of space.