Simplify the expression: (3x2y3)\ot(2x−1y4)(3x^2 y^3) \ot (2x^{-1} y^4)(3x2y3)\ot(2x−1y4).
6xy76xy^76xy7
6x3y76x^3 y^76x3y7
5xy75xy^75xy7
6xy126x y^{12}6xy12