If two towers of height $h_1$ and $h_2$ subtend angles $60^{\circ} $ and $30^{\circ}$ respectively at the mid point of the line joining their feet, then $h_1:h_2$ is equal to:

Question

( A ) $2:1$
( B ) $1:3$
( C ) $1:2$
( D ) $3:1$