The following figure shows the age pyramids for human populations. What types of populations are represented by $P$,$Q$,and $R$?
$P \quad\quad Q \quad\quad R$

• A
  Declining population $\quad$ Expanding population $\quad$ Stable population
• B
  Stable population $\quad$ Expanding population $\quad$ Declining population
• C
  Expanding population $\quad$ Stable population $\quad$ Declining population
• D
  Declining population $\quad$ Stable population $\quad$ Expanding population