In triangle $\bigtriangleup ABC, \angle B = 70^{\circ} and \angle C = 40^{\circ}.$ If point D is on line BC such that AD bisects $\angle A$. Find angle $\angle{ADB}$.

Question

$( A ) 75^{\circ} \\ ( B ) 65^{\circ} \\ ( C ) 15^{\circ} \\ ( D ) 80^{\circ}$