Which of These Statements MOST Accurately Characterizes the Abundance of Quasars

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.