How many flights occur daily over UK airspace?

Answer: B — Over 6000

The correct answer indicates that over 6000 flights occur daily over UK airspace. This figure is supported by air traffic data that reflects the high level of air travel activity in the UK, which is one of the busiest airspaces in Europe. In order to arrive at this answer, it is important to recognize that daily operations in UK airspace involve a significant number of domestic and international flights. The United Kingdom serves as a critical hub for international travel, connecting to numerous global destinations. As such, the average number of flights can exceed 6000 on a typical day, especially during peak travel seasons. When analyzing the other options, while it's certainly plausible that the number of daily flights could fluctuate and even fall into higher ranges, the specific data consistently points to the figure being over 6000 as a more accurate representation popular among sources monitoring air traffic. The record of air traffic management also typically confirms this average during routine operations.