In order to find the perpendicular line, we need to know that perpendicular lines have the following relation about their slopes:
So first, let's find the slope of the given equation, putting it in the slope-intercept form (y = mx + b, m is the slope):
The slope is m1 = 1/5. So the slope of any perpendicular line is:
So the perpendicular line has the model y = -5x + b
Therefore the correct option is C.