The solvolysis of $(\mathrm{C}{}_6\mathrm{H}{}_5){}_2\mathrm{CH}-\mathrm{Cl}$ is described by $\mathrm{RCl}\underset{\mathrm{k}{}_{-1}}{\overset{\mathrm{k}{}_1}{\rightleftharpoons }}\mathrm{R}{}^{+}+\mathrm{Cl}{}^{-}$ followed by fast capture of $\mathrm{R}{}^{+}$ by solvent with rate constant $k_2$, so that $k_{obs}=k_1/(1+(k_{-1}/k_2)[\mathrm{Cl}{}^{-}])$. Without added chloride $k_{obs}=8.0\times 10^{-4}{\mathrm{s}}^{-1}$, and with $0.10\mathrm{M}$ added $\mathrm{LiCl}$ it is $5.0\times 10^{-4}{\mathrm{s}}^{-1}$ (ignore any other salt effects). The $k_{obs}$ in the presence of $0.30\mathrm{M}$ chloride is

1. A$2.86\times 10^{-4}{\mathrm{s}}^{-1}$
2. B$5.00\times 10^{-4}{\mathrm{s}}^{-1}$
3. C$1.67\times 10^{-4}{\mathrm{s}}^{-1}$
4. D$6.78\times 10^{-4}{\mathrm{s}}^{-1}$