Based on an architectural drawing, a roof slopes to a drain along the function represented in the table that defines

Based on an architectural drawing, a roof slopes to a drain along the function represented in the table that defines the edge of slope, where x is the horizontal distance in feet and f(x) is the vertical distance in feet.
If the drain is at the minimum point, how far is it from the wall defined by the y-axis?
0 feet
8 feet
80 feet
160 feet