Match the line described on the left with the slope of the line on the right:
1. y = 0
2. 3y = 18
3. 9x
4. The line through (4, -1) and (8, 7)
5. The line through (-5, 7) and (-5, -8)
Option:
A. Slope is undefined
B. Slope is 9
C. Slope is 3
D. Slope is undefined
E. Slope is 2