Answer:
C, B
Explanation:
Basically to find the slope you take the rise over run. How many squares does the line go up, over how many does it go left or right. As you can see in the diagram, it goes up 2 squares and goes left 1 square, giving the slope 2/1, which is 2.
The slope of a horizontal line is straight, which means it goes up 0, so automatically your answer is zero, because dividing anything by 0 is 0.