Answer: D. 9x^4y^8√3x
Explanation:
We can simplify the expression as follows:
√243x^9 y^16 = √(81*3) * x^4 * x^5 * y^8 * y^8
Using the rule of exponents (a^m * a^n = a^(m+n)):
√(81*3) * x^4 * x^5 * y^8 * y^8 = 9xy^8 * x^4√3
Therefore, the simplified expression is:
D. 9x^4y^8√3x