What impact does temperature have on GFP's fluorescence?

The choice that indicates temperature can increase or decrease fluorescence is correct because temperature has a significant effect on the behavior and stability of proteins, including GFP. At lower temperatures, fluorescent proteins may experience reduced molecular motion, potentially leading to increased stability and fluorescence intensity. Conversely, at higher temperatures, while some proteins might remain stable, the increased molecular motion and possible denaturation can lead to decreased fluorescence. This means that depending on the specific temperature conditions, the fluorescence of GFP can indeed either increase or decrease as a result of these thermal effects on protein structure and conformation. Thus, temperature plays a vital role in modulating the fluorescence properties of GFP, making the understanding of thermal effects essential in experiments involving this protein.