Four students were discussing how to find the unit rate for a proportional relationship "Look at the graph of the relationship. Find the y-value of the point that correspo rate." O "Look at the graph of the relationship. Count the number of units up and the nun move to arrive at the next point on the graph. Write these two numbers as a frac O "Look at the graph of the relationship. Find the x-value of the point that correspo rate." O "Look at the graph of the relationship. Find two points which have y-values that the difference in the corresponding X-values."​