Option B.
5xβ2)(4x^2β3xβ2)
=(5x+β2)(4x^2+β3x+β2)
=(5x)(4x^2)+(5x)(β3x)+(5x)(β2)+(β2)(4x^2)+(β2)(β3x)+(β2)(β2)
=20x^3β15x^2β10xβ8x^2+6x+4
=20x^3β23x^2β4x+4