which of the following expressions does not equal: the sixth root of 81x^4y^8
A(3xy^2)^2/3
B(3x)^2/3y^4/3
C(3x^2y^4)^1/3
Dcube root of 9x^2y^4
A(3xy^2)^2/3
B(3x)^2/3y^4/3
C(3x^2y^4)^1/3
Dcube root of 9x^2y^4