Both Statement I and Statement II are correct, and Statement II explains Statement I because certain rare earth elements, such as europium and terbium, are integral to the phosphorescent materials used in the production of screens. These elements are essential for the function of liquid crystal displays (LCDs) and light-emitting diodes (LEDs), contributing to the vivid colors and brightness seen in modern flat-screen televisions and computer monitors. This illustrates the technological significance of rare earth elements in electronic displays, aligning with core concepts in materials science covered in UPSC syllabus sources.