Which of the following statements is incorrect?

• A
  $Mg$ burns in air to give a dazzling light rich in $UV$ rays.
• B
  $CaCl_2 \cdot 6H_2O$ gives a freezing mixture when mixed with ice.
• C
  $Mg$ cannot form complex salts.
• D
  $Be$ can form complexes due to its small size.