Answer: C. $2/hour
Each time the number of hours (on the x axis) goes up by 1, the cost (on the y axis) goes up by up by $2. So each hour costs $2.
You can pick two points on the graph, such as (1,2) and (2,4) to compute the slope using the slope formula below
m = (y2 - y1)/(x2 - x1)
m = (4-2)/(2-1)
m = 2/1
m = 2 we get a slope of 2
The slope is the rise/run
rise = change in cost = change in y
run = change in time = change in x
