The steel frame (E = 200 GPa) shown has a diagonal brace BD with an area of 1920 mm. Determine the largest allowable load P if the change in length of member BD is not to exceed 1.6 mm. = 50 kN a) P b) P = 60 kN c) P = 80 kN d) P = 10 kN e) P = 15 kN 6 m B 5 m Figure Q.28 D P