An expert issued a statement on the current multiple parties' questions about the safety of regional aviation. He said that the safety standards implemented by regional aircraft are basically the same as those of Boeing and Airbus, and the structural strength of large and small aircraft is the same. Passengers feel that regional aircraft are bumpy It is because the larger the aircraft, the stronger the anti-interference ability, so it feels smooth. In fact, there is no difference in safety between regional aircraft and mainline aircraft. Which of the following, if true, would most question the expert's point of view? ['In recent years, the development of regional aviation in China has been too fast, and the problems of regional airport management and equipment lag have become increasingly prominent.', 'In mature aviation markets such as North America and Europe, regional aviation accounts for nearly 40%.', 'In an aviation accident, it is very important that passengers have the ability to leave the aircraft in a timely manner.', 'Some patients with cardiovascular and cerebrovascular diseases are unwilling to take a regional flight.']