What concept is closely related to the situation

Assume that Alex was working in an IT company for 3 months now. However, he found that he did not like the job because he disliked sitting for hours in front of the computer and working on codes that did not interest him. He thought about it and decided to move to a new career in teaching with the knowledge he acquired in the IT company while doing research that he is actively interested in. He quitted his job and is now finding a new one. Say he is not in a university yet. What kind of unemployment will be most closely related this job loss?

1. Frictional unemployment
2. Cyclical unemployment
3. Structural unemployment
4. Discouraged unemployment