What is the domain of the square root function graphed below?

On a coordinate plane, a curve opens down to the right and goes through quadrants 1 and 2. The curve starts at (negative 4, 0) and goes through (negative 3, 1) and (0, 2).
x greater-than-or-equal-to negative 4
x greater-than negative 4
x greater-than-or-equal-to 0
x greater-than 0