Which of the following statement are correct

Question

$\begin{array}{1 1} \text{(a) chemical name of bleaching powder is calcium oxychloride} \\ \text{ (b) Bleaching powder is used for sterilization of drinking water} \\ \text{ (c) Bleaching powder is manufactured by Hasenclever?s plant } \\ \text{ (d) All of these} \end{array}$