1. The problem asks for the slope of the line given by the equation $y = -5x + 8$. 2. Recall that the slope-intercept form of a line is $y = mx + b$, where $m$ is the slope and $b$ is the y-intercept. 3. In the equation $y = -5x + 8$, the coefficient of $x$ is $-5$, so the slope $m = -5$. 4. Therefore, the slope of the line is $-5$. 5. Among the options given, the correct answer is d) $-5$.