Two cars are travelling on the same straight road in the same direction. Car B is travelling at the constant speed of $72$ $km/hr$. Car A is travelling at the constant speed $v_A$, approaching Car B from behind. The driver of Car B notices Car A when it is still $60$ $m$ behind him. Car B accelerates at the constant rate of $0.75$ $m/s^2$ to avoid being struck by car A. Knowing that the closest that A comes to B is $6$ $m$, determine the speed $v_A$ of car A.

A. $39.8$ $km/hr$
B. $86.5$ $km/hr$
C. $93.4$ $km/hr$
D. $104.4$ $km/hr$
E. $130.1$ $km/hr$
F. $174.6$ $km/hr$