Which statement from the passage best supports the idea that the flight training program was difficult?

The airline industry has a high demand for pilots; however, the ability to train new ones and recruiting them is very challenging. The experience required determines the capability of wringing. This is because the industry is susceptible and requires more training. Besides training itself is very expensive and may take long time for one to be fully considered a pilot. The process, therefore, may slow down the recruitment process thus making it a challenge to the airline and the entire workers.