Recently I took a two-leg flight connection entirely inside the EU. The flight A --> B ended up delayed, and as a result I missed the B --> C connection. The airline rebooked me and I arrived at C a day late.

I applied for the EU compensation, but the airline refused. I would like to complain to the "national authority". According to the [EU guidance][1], it should be the "national authority in the country where the incident took place". A, B and C are all in different countries. Which of them is the proper one to lodge the complaint?


  [1]: https://europa.eu/youreurope/citizens/travel/passenger-rights/air/index_en.htm#next-steps-5