Final answer:
The slope of a line parallel to the equation y = -x or y = -x + 1 will also have a slope of -1, leading to the answer C.O-1.
Step-by-step explanation:
The student has asked to find the slope of a line that is parallel to the given equation. However, there seems to be a typographical error in the provided equation, as it should likely be in the form y = mx + b, where m is the slope. Assuming the correct equation is either y = -x or y = -x + 1, lines that are parallel to this will have the same slope. Since the slope (m) in the equation y = -x or y = -x + 1 is -1, any line parallel to this will also have a slope of -1. Therefore, the answer to the question is C.O-1.