Which law is followed by the different proportions of oxygen in various oxides of nitrogen?

Which one of the following pairs of compounds illustrates the law of multiple proportions?

When two elements combine to form more than one compound,the masses of one element that combine with a fixed mass of the other element are in a simple whole number ratio.
$(a)$ Is the statement given above correct?
$(b)$ If 'yes',which law does it follow?
$(c)$ Give an example corresponding to this law.

Two elements $x$ and $y$ have atomic masses $14$ and $16$ respectively. They form a series of five compounds $A, B, C, D, E$ in which the ratio of $x$ to $y$ is $1:2:3:4:5$. If compound $A$ contains $28$ parts by weight of $x$ and $16$ parts by weight of $y$,then in compound $C$,how many parts by weight of $x$ will combine with $24$ parts by weight of $y$?

In two compounds,each containing tin $(Sn)$ and oxygen,the composition is as follows. Which law of chemical combination can be illustrated by this data?

Compound	$\% Sn$	$\% O$
$A$	$78.77$	$21.23$
$B$	$88.12$	$11.88$

Hydrogen combines with oxygen to form $H_2O$ in which $16 \ g$ of oxygen combine with $2 \ g$ of hydrogen. Hydrogen also combines with carbon to form $CH_4$ in which $2 \ g$ of hydrogen combine with $6 \ g$ of carbon. If carbon and oxygen combine together then they will do so in the ratio of