The function f(x)=sqrt -x is shown on the graph. Which statement is true?
A-The domain of the function is all real numbers greater than or equal to 0.
B-The range of the function is all real numbers greater than or equal to −1.
C-The range of the function is all real numbers less than or equal to 0.
D-The domain of the function is all real numbers less than or equal to 0.