The law of definite proportions is not applicable to nitrogen oxides because

One part of an element $A$ combines with two parts of another element $B$. Six parts of the element $C$ combine with four parts of the element $B$. If $A$ and $C$ combine together,the ratio of their weights will be governed by

Ammonia contains $82.35\%$ nitrogen and $17.65\%$ hydrogen. Water contains $88.90\%$ oxygen and $11.10\%$ hydrogen. Nitrogen dioxide contains $63.15\%$ oxygen and $36.85\%$ nitrogen. Which law can be illustrated by the given data?

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

Which of the following statements is correct about the given reaction?
$4Fe_{(s)} + 3O_{2_{(g)}} \to 2Fe_{2}O_{3_{(s)}}$

$1 \, L$ of $N_2$ combines with $3 \, L$ of $H_2$ to form $2 \, L$ of $NH_3$ under the same conditions. This illustrates the: