A power transmission line feeds input power at $2300\;v$ to a step down transformer , with its primary winding's having $4000$ turns. What should be the number of turns in the secondary windings in order to get out put power at $230\;v$

Question

$\begin{array}{1 1} 40 \\ 400 \\ 4000 \\ none\;of\;the\;above \end{array}$