An $L$-shaped object, made of thin rods of uniform mass density, is suspended with a string as shown in figure. If $A B = B C$, and the angle made by $A B$ with downward vertical is $\theta$, then:\\
(1) $\tan \theta = \frac { 2 } { \sqrt { 3 } }$\\
(2) $\tan \theta = \frac { 1 } { 3 }$\\
(3) $\tan \theta = \frac { 1 } { 2 }$\\
(4) $\tan \theta = \frac { 1 } { 2 \sqrt { 3 } }$