Concept:Use integration by parts to integrate the product of a polynomial and a logarithmic function.Explanation:Let u=logx and dv=x3dx.Then du=x1dx and v=4x4.Applying integration by parts: ∫udv=uv−∫vdu.Therefore:∫x3logxdx=4x4logx−∫4x4⋅x1dxSimplify the integral:=4x4logx−41∫x3dx=4x4logx−41⋅4x4+c=4x4logx−16x4+cFactor out 16x4:=16x4[4logx−1]+cAnswer:Option A: 16x4[4logx−1]+c