In a region with magnetic declination of $2^{\circ}E$, the magnetic Fore bearing (FB) of a line $AB$ was measured as $N79^{\circ}50’E$. There was local attraction at $A$. To determine the correct magnetic bearing of the line, a point $O$ was selected at which there was no local attraction. The magnetic $FB$ of line $AO$ and $OA$ were observed to be $S 52^{\circ} 40’E$ and $N50^{\circ}20’W$, respectively. What is the true $FB$ of line $AB?$

1. $N81^{\circ}50’E$
2. $N82^{\circ}10’E$
3. $N84^{\circ}10’E$
4. $N77^{\circ}50’E$