Answer:
x≥0 is correct inequality.
D is correct.
Explanation:
We are given a function

We need to find x where function is defined.
As we know negative inside the root not defined.
Inside the root value must be greater than equal to 0.
Here we have inside the root is x.
Therefore, x must be greater than equal to 0.
Inequality: x≥0
Please see attached graph for more clarification.
Hence, x≥0 is correct inequality.