Which expression is equivalent to sqrt [7](x^9y^9) where a and y are positive? A (xy)^(7)/(9) B (xy)^(9)/(7) C (xy)^16 D (xy)^63 (D

To find the expression equivalent to , we need to simplify the radical expression.The given expression is , which can be written as .Using the property of exponents, we can simplify this expression further. .Therefore, the expression equivalent to is .So, the correct answer is option B: .