Identify the isoelectronic species from the following.

• A
  $K^{+}, Ca^{2+}, Sc^{3+}, Cl^{-}$
• B
  $Na^{+}, Mg^{2+}, Al^{3+}, Cl^{-}$
• C
  $K^{+}, Cl^{-}, Mg^{2+}, Sc^{3+}$
• D
  $Na^{+}, Ca^{2+}, Sc^{3+}, F^{-}$