A student places a fresh battery in a flashlight. The student leaves the flashlight switched on for several hours. The student observes that the flashlight gets dimmer over time. Which argument does this observation support?

well in order to answer this question you have to provide more information < 3

on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.