Answer: B
Step-by-step explanation: When dividing by exponents you substract them so
(9x^3y^-10z^6)/(3xy^2z^-3)
We can first divide 9 by 3 which equals 3
so 3x^3y^-10^z^6/xy^2z^3
then subtract exponents x^3/x = x^2, y^-10/y^2 = y^-12, z^6/z^-3 = z^9
and then we will put y on the denominator and change the exponent's sign so 3x^2z^9/y^12