ANSWER
[tex]x \geqslant 3[/tex]
EXPLANATION
The domain of a function refers to the set of x-values for which the graph of the function exists.
From the graph provided, the graph of the function exists for x-values greater than or equal to 3.
Therefore the domain of the square root function graphed is
[tex]x \geqslant 3[/tex]
The correct choice is the fourth option.
