$f_y=300\mathrm{MPa}$，$A_s=8\times153.9=1231\mathrm{mm^2}$。$\alpha_v=(4.0-0.08\times14)\sqrt{14.3/300}=0.629$，$\alpha_b=0.6+0.25\times20/14=0.957$，$\alpha_r=0.85$。拉力F分解为$N=V= \frac{\sqrt{2}}{2}F$。由式(9.7.2-3)：$\frac{V-0.3N}{\alpha_r\alpha_v f_y}+\frac{M-0.4Nz}{1.3\alpha_r\alpha_b f_y z}\le A_s$，代入得$F\le266\mathrm{kN}$。由式(9.7.2-4)：$\frac{M-0.4Nz}{0.4\alpha_r\alpha_b f_y z}\le A_s$，得$F\le416\mathrm{kN}$。取小值，考虑2列4层共8根，实际$F=266$，选项A最接近。