1. The problem asks to simplify the radical expression assuming all variables are nonnegative real numbers. 2. Since the user did not provide the exact radical expression, but options suggest powers of $x$, we consider a common radical simplification scenario such as simplifying $\sqrt{x^6}$. 3. The formula for simplifying radicals is $\sqrt{x^n} = x^{\frac{n}{2}}$ when $x \geq 0$. 4. Applying this to $\sqrt{x^6}$, we get $x^{\frac{6}{2}} = x^3$. 5. Therefore, the simplified form is $x^3$. 6. Among the options, Option A and Option C both show $x^3$, which is the correct simplification. 7. Hence, the simplified radical is $x^3$.