Given the graph that shows the results of the survey, you know that it shows the results of 3 price surveys conducted at 4 area supermarkets in 3 months.
Notice that the white bar represents the results of September, the dashed bar represents the results in November and the black bar represents the results in March.
You can identify that on the x-axis are written the 4 area supermarkets and, on the y-axis are represented the prices in dollars.
Therefore, in order to identify the supermarket that lowered the price of the frozen beef dinners by the greatest dollar amount between September and November, you need to identify the supermarket that has the shortest dashed bars and white bars.
In this case, you can identify that the lowest price in September and November is:
And it corresponds to Warehouse.
Hence, the answer is: Option (2).