The correct statement (s) about the oxoacids, ${\mathrm{HClO}}_4$  and  $\mathrm{HClO},$  is (are)

The conjugate base of  $HCl{O}_4$  is a weaker base than ${\mathrm{H}}_2\mathrm{O}$  

${\mathrm{HClO}}_4$  is formed in the reaction between ${\mathrm{Cl}}_2$   and  ${\mathrm{H}}_2\mathrm{O}$

${\mathrm{HClO}}_4$  Is more acidic than $\mathrm{HClO}$   Because of the resonance stabilization of its anion 

The central atom in both $\mathrm{HOCl}$  and ${\mathrm{HClO}}_4$  is $s{p}^3$   hybridised