Which of the following statements is correct for $CsBr_3$?

• A
  It is a covalent compound.
• B
  It contains $Cs^{3+}$ and $Br^-$ ions.
• C
  It contains $Cs^+$ and $Br_3^-$ ions.
• D
  It contains $Cs^+$,$Br^-$,and $Br_2$ molecules.