Which of the following represent the correct order of decrease in covalent character?

Question

$\begin{array}{1 1}(a)\; BaCl_2 > SrCl_2 > CaCl_2 > MgCl_2 > BeCl_2\\(b)\; BeCl_2 > MgCl_2 > CaCl_2 > SrCl_2 > BaCl_2\\(c)\; BaCl_2 > SrCl_2 > CaCl_2 > BeCl_2 > MgCl_2\\(d)\; BaCl_2 > CaCl_2 > SrCl_2 > BeCl_2 > MgCl_2\end{array}$