This cross bracing is made of 8-in schedule 40 pipe, which has an inner diameter of 7.981 in, and outer diameter of 8.625 in. The end of these cross braces consists of a 7/8-in- thick plate welded into a slot cut in the pipe, as shown. How long (L) must the welds be such that when the pipe yields in tension (at 36 ksi), the max shear stress in the welds is 18 ksi? See details of weld below. Cross section, showing four % in welds A. 5.8 in. B. 9.5 in. C. 12 in. D. 15 in.