Which of the following compounds has a peroxide linkage?

In which of the following reactions is hydrogen peroxide $(H_2O_2)$ a reducing agent?

$3.4 \ g$ of $H_2O_2$ is present in its $112 \ mL$ solution. The volume strength of this solution is ....... $V$.

Among the statements $(a) - (d)$,the correct ones are:
$(a)$ Decomposition of hydrogen peroxide gives dioxygen.
$(b)$ Like hydrogen peroxide,compounds such as $KClO_{3}$,$Pb(NO_{3})_{2}$,and $NaNO_{3}$ liberate dioxygen when heated.
$(c)$ $2$-Ethylanthraquinone is useful for the industrial preparation of hydrogen peroxide.
$(d)$ Hydrogen peroxide is used for the manufacture of sodium perborate.

$A$ : The $O-O$ bond length in $H_2O_2$ is smaller than that in $O_2F_2$.
$R$ : $H_2O_2$ is an ionic compound.

Which one of the following is reduced by hydrogen peroxide in acid medium?