4.7-8 The frame shown in Figure P4.7-8 is unbraced, and bending is about the x-axisof the members. All beams are W18 x 35, and all columns are W10 × 54. a. Determine the effective length factor K for column AB. Do not considerthe stiffness reduction factor. b. Determine the effective length factor K for column BC. Do not considerthe stiffness reduction factor. If F, = 50 ksi, is the stiffness reduction factor applicable to these columns?