The universal Gravitation constant $'G'$ is directly proportional to the product of the masses $m_1$ and $m_2$ and inversely proportional to the square of the distance between them ( $r$ ). The correct way of representing this is

Question

$\begin{array}{1 1} (a)\; G \propto \frac{m_1}{m_2r^2} \\ (b)\; G \propto \frac{m_1+m_2}{r^2} \\ (c)\; G \propto \frac{m_1m_2}{r^2} \\ (d)\; G \propto \frac{r^2}{m_1m_2} \end{array}$