11. 如右圖所示,若薄壁斷面之容許剪應力為 求其能承受之最大扭矩為何? (A) 1382.6 kg ⋅ cm (B) 1497.6 kg ⋅ cm (C) 1573.6 kg ⋅ cm (D) 1662.6 kg ⋅ cm