Which of These Statements MOST Accurately Characterizes the Abundance of Quasars

question 9

Multiple Choice

Which of these statements MOST accurately characterizes the abundance of quasars over the universe's history?

• A) Quasars were most common very early in the universe's history, about 100 million years after the Big Bang, and their abundance has been declining ever since.
• B) Quasars have been increasing in abundance over time, so that they are most common today.
• C) Quasars peaked in their abundance about 11-12 billion years ago.
• D) Quasars go through cycles in which their abundance increases dramatically then decreases. At the present day, they are at a low point in the cycle.