Multiply out (x2 + 3xy - y)(3x + y) using polynomial long multiplication.A3x3 + 12x2y + xy2 - 3xy - y2B3x3 + 10x2y + 3xy2 - 3xy + y2C3x3 + 10x2y + 3xy2 - 3xy - y2D3x3 + 8x2y + 3xy2 - 3xy - y2