The correct statement(s) regarding,
(i) $\mathrm{H}\mathrm{C}\mathrm{l}\mathrm{O}$
(ii) $\mathrm{H}\mathrm{C}\mathrm{l}{\mathrm{O}}_2$
(iii) $\mathrm{H}\mathrm{C}\mathrm{l}{\mathrm{O}}_3$ and
(iv) $\mathrm{H}\mathrm{C}\mathrm{l}{\mathrm{O}}_4$ is /are

• A

  The number of $\mathrm{C}\mathrm{l}=\mathrm{O}$ bonds in (ii) and (iii) together is two.
• Correct answer
  B

  The number of lone pairs of electrons on Cl in (ii) and (iii) together is three.
• Correct answer
  C

  The hybridization of Cl in (iv) is $\mathrm{s}{\mathrm{p}}^3$
• D

  Amongst (i) to (iv), the strongest acid (i)

Hence, the correct answer is options: 'B', 'C'.