Which one of the following is a set of solution of the equation \({{\rm{x}}^{\sqrt {\rm{x}} }} = \sqrt[{\rm{n}}]{{{{\rm{x}}^{\rm{x}}}}}\) if n is a positive integer?

• A. {1, n2}
• B. {1, √n}
• C. {1, n}
• D. {n, n2}