Which of the following statements is not true about the $NaCl$ structure?

• A
  $Cl^{-}$ ions are in $fcc$ arrangement.
• B
  $Na^{+}$ ions have a coordination number of $4$.
• C
  $Cl^{-}$ ions have a coordination number of $6$.
• D
  Each unit cell contains $4$ $NaCl$ molecules.