$12g$ of carbon combines with $64g$ sulphur to form ${CS}_2$. $12g$ carbon also combines with $32g$ oxygen to form ${CO}_2$. $10g$ sulphur combines with $10g$ oxygen to form ${SO}_2$. These data illustrate the

The correct option is D Law of reciprocal proportions
Given,

$12g$ $C$ combines with $64g$ $S$ to give $C{S}_2$

$12g$ $C$ combines with $32g$ $O$ to give $C{O}_2$

Also, $10gS$ combines with $10gO$ to give $S{O}_2$

In $C{S}_2$ $C:S=12:64=3:16$

In $C{O}_2$ $C:O=12:32=3:8$

From, $C{S}_2$ & $C{O}_2$, $S:O=16:8=2:1$

Also in $S{O}_2$ $S:O=10:10=1:1$

$\Rightarrow 2:1$ is multiple of $1:1$

$\frac{1}{1}\times 2=\frac{2}{1}$

$\Rightarrow$ Law of reciprocal proportions is illustrated here.