Final answer:
The equation y = -5x represents a diagonal line with a negative slope, meaning it descends as it moves from left to right on a graph. The correct option is D.
Step-by-step explanation:
The equation y = -5x represents a diagonal line. This line has a negative slope, which means it moves downward on the graph as the x-value increases. The slope is determined by the coefficient of x, which in this case is -5. Because the line has a slope that is not equal to zero, it is not a horizontal line.
Additionally, this line is not parallel to the x-axis or the y-axis, and because there is no second line to compare with, we cannot say it is perpendicular without more information.
Hence, Option D is correct.