I believe the correct answer would be A, B and C. For A, (xy^2)^2= x^2 y^4, we distribute the exponent on the outermost side to the inner ones and multiplying it to the exponent of each variable. For B, we can combine the variables since they have the same base and we add their exponents. For C, when the exponent of a variable is negative it means it is 1 over that term.
