Which statement is true about the function f(x)=-x ? a). the domain of the graph is all real numbers. b). the range of the graph is all real numbers. c). the domain of the graph is all real numbers less than or equal to 0. d). the range of the graph is all real numbers less than or equal to 0.

Both (A) and (B) are true, but if you have to choose one I'd go with (A). The domain is all real numbers because you can put any number (rational or irrational) for x and you get a value. The range is all real numbers because there is an x you could plug in to get any real number.

But (A) is the better answer if you can only choose one.