Task: Question Generation
Input (English): Background Paragraph: A neon light produces visible light by electroluminescence. In this process, neon or some other gas gives off light when an electric current passes through it. Other halogen gases besides neon—including krypton and argon—also produce light in this way. The word “OPEN” in the sign below is a neon light. It is a long glass tube that contains neon gas. When electricity passes through the gas, it excites electrons of neon atoms, and the electrons jump to a higher energy level. As the excited electrons return to their original energy level, they give off visible light. Neon produces red light. Other gases produce light of different colors. For example, krypton produces violet light, and argon produces blue light. 
Story: John and Jacob are both store owners hoping to attract more attention to their stores by using neon signs. Since both of them will be in their store for so many hours, they want to use neon signs that produce their favorite colors. John's favorite color is violet, while Jacob's favorite color is blue.
Output (English): Who would prefer to use a krypton sign?