Two planets $A$ and $B$ of equal mass are having their period of revolutions $T_A$ and $T_B$ such that $T_A=2 T_B$. These planets are revolving in the circular orbits of radii $\mathrm{r}_{\mathrm{A}}$ and $\mathrm{r}_{\mathrm{G}}$ respectively. Which out of the following would be the correct relationship of their orbits?