Oxidation number of oxygen in ozone $(O_3)$ is

$A$ compound contains three elements $A$,$B$,and $C$. If the oxidation numbers are $A = +2$,$B = +5$,and $C = -2$,the possible formula of the compound is:

Match the following:

Compound	Oxidation number
$1$. $CrO_5$	$a$. $+6$
$2$. $H_2SO_4$	$b$. $+1$
$3$. $C_4OCl_2$	$c$. $-1$
$4$. $(CH_3)_2SO$	$d$. $+2$

In which of the following substances is the oxidation state of sulfur $-1$?

The oxidation states of three carbon atoms in carbon suboxide $(C_3O_2)$ respectively are

In $NH_4NO_2$,the oxidation number of nitrogen will be