Choose the incorrect option from the following.

Aryl diazonium salts are stable at very low temperature 

Aryl diazonium salts are less stable than alkyl diazonium salts

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{N}}_2^{+}{\mathrm{HSO}}_4^{-}$ is named as benzene diazonium hydrogen sulphate

Alkyl diazonium salts are highly unstable