The experience of a department store with a large skylight has shown that sales of sunlight into the mall can increase sales. The large skylight of the department store allows sunlight to enter half of the mall, which can reduce the need for artificial lighting. The place has only artificial lighting. Since the mall opened two years ago, the sales volume of each department on the side of the skylight is much higher than that of other departments. If true, the one that best supports the above discussion is:. ['In addition to the skylight, there are some obvious differences between the two parts of the building.', 'On some cloudy days, more artificial light is needed to illuminate the area under the skylight in the mall.', "During the mall's opening hours at night, the sales of each department under the skylight in the mall are not higher than other departments.", "Departments located in the lower part of the mall's skylight, also among the other chain stores in the mall with the highest sales."]