কোনটি চার্লসের সূত্র?

$P \propto \frac{1}{V}(\text { at constant } T)$

$\mathrm{V} \propto \frac{1}{\mathrm{~T}}(\text { at constant } \mathrm{P})$

$\mathrm{V} \propto \mathrm{T}(\text { at constant } \mathrm{P})$

$\mathrm{P} \propto \mathrm{T}(\text { at constant } \mathrm{V})$