An conic compound is expected to have tetrahedral structure if $\large\frac{r^+}{r^-}$ lies in the range of

Question

$\begin{array}{1 1} 0.414\;to \;0.732 \\ 0.732 \;to\;1 \\ 0.155 \;to \;0.225 \\ 0.225\;to \;0.414\end{array} $