Assume x is the independent variable and x has a domain. So y as the dependent variable has a range determined by the domain of x. So the answer has to be values of y, not x. Answer C contains the 5 values of y in order least to greatest. We don't know whether the relationship is continuous, so for the 5 values of x we need 5 values for y. We can't say that the range is [-7,5] because we don't know what happens to y for other values of x. Answer C seems to be the only valid solution.