Choose the false statement from the following.

• A
  Good yield of alkyl halide may be obtained by heating alcohols with $NaI$ in $95 \% \ H_3PO_4$.
• B
  Constant boiling $HBr \ (48 \%)$ is used for the preparation of alkyl bromides from alcohols.
• C
  Tertiary alcohols readily react with conc. $HCl$ in the absence of zinc chloride.
• D
  The order of reactivity of alcohols with a given halo acid is $1^{\circ} > 2^{\circ} > 3^{\circ}$.