When water is added to bleaching powder, it produces—

• a$\mathrm{CaCl_2}$ and $\mathrm{HOCl}$
• b$\mathrm{Ca(OH)_2}$ and $\mathrm{HCl}$
• c$\mathrm{CaO}$ and $\mathrm{HOCl}$
• d$\mathrm{CaCO_3}$ and $\mathrm{HCl}$