Tim Kaver his home and walks 10 minutes due west and then 5 minutes due south. What can be the shortest time he could walk from the current position to his house ?

Question

$\begin{array}{1 1} (a)\; 2 \sqrt{5} \\ (b)\; 5 \sqrt{5} \\ (c)\; 10\sqrt{5} \\ (d)\; \sqrt{5} \end{array}$