An isothermal steady state mixed flow reactor $(CSTR)$ of $1\:m^{3}$ volume is used to carry out the first order liquid-phase reaction $A{\rightarrow}$ products. Fresh feed at a volumetric flow rate of $Q$ containing reactant $A$ at a concentration $C_{A0}$ mixea with the recycle stream at a volumetric flow rate $RQ$ as shown in the figure below.

It is observed that when the recycle ratio $R=0.5$, the exit conversion $X_{Af}=50\%$. When the recycle ratio is increased  to $R=2$, the new exit conversion (in percent) will be :

1. $50.0$
2. $54.3$
3. $58.7$
4. $63.2$