I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "Incandescent bulbs have been replaced in many applications by other types of electric light, such as fluorescent lamps, compact fluorescent lamps (CFL), cold cathode fluorescent lamps (CCFL), high-intensity discharge lamps, and light-emitting diode lamps (LED). Some jurisdictions, such as the European Union, China, Canada and United States, are in the process of phasing out the use of incandescent light bulbs while others, including Colombia, Mexico, Cuba, Argentina, Brazil and Australia, have prohibited them already."? 

Incandescent bulbs have become obsolete in many countries, and indeed in a few others they have been banned altogether. With this stated, what is their successor?