Compound (A) contains Cl in its structure, and Cl has uninegative and unipositive charge in compound (A). On long-standing, compound (A) undergoes auto oxidation and form (B) and (C), but in presence of ${\mathrm{CoCl}}_2$ catalyst it forms P and D. B is also produced when compound (A) reacts with ${\mathrm{H}}_2\mathrm{S}$ gas.

Which of the fol lowing statements are correct about (A)?

Since chlorine needs moisture to work as a bleach, it bleaches by the process of oxidation. Hydrochloric acid is created when chlorine combines with water. This unstable acid soon dissociates to produce nascent oxygen.
Chlorine is used to create organic substances including ${\mathrm{CHCl}}_3, {\mathrm{CCl}}_4, \mathrm{DDT}$, dyes, and pharmaceuticals.
Mustard gas, which may be modelled by the formula, is one of the toxic gases that are created using ${ }_{ }{\mathrm{Cl}}_2$.
Chlorination is the process of disinfecting drinking water by introducing chlorine to eradicate viruses, germs, and parasites.

$\mathrm{A}\to {\mathrm{CaOCl}}_2;\mathrm{B}\to {\mathrm{CaCl}}_2;\mathrm{C}\to \mathrm{Ca}{\left({\mathrm{ClO}}_3\right)}_2;\mathrm{D}\to {\mathrm{O}}_2$