Notice that the number of customers increases as the temperature increases. The line of best fit will go up as you follow the graph from left to right, so eliminate (B) and (D). To determine if the correct graph is (A) or (C), try roughly plotting the data points, and then look at your graph. Notice that the number of customers does not increase by the same number for each 10-degree temperature increase. This is an exponential increase, not a linear increase. Therefore, the graph will be curved. Eliminate (C). Only (A) fits the data in the chart.