The correct order of thermal stability of hydroxides is :

Question

$\begin{array}{1 1} Ba(OH)_2 < Sr(OH)_2 < Ca(OH)_2 < Mg(OH)_2 \\ Ba(OH)_2 < Ca(OH)_2 < Sr(OH)_2 < Mg(OH)_2 \\ Mg(OH)_2 < Ca(OH)_2 < Sr(OH)_2 < Ba(OH)_2 \\ Mg(OH)_2 < Sr(OH)_2 < Ca(OH)_2 < Ba(OH)_2 \end{array} $