- The formation of something is a kind of process
- Nuclear fusion causes star formation
- If something causes a process then that something is required for that process
- Therefore, nuclear fusion is required for star formation

- Nuclear fusion is required for star formation
- If something requires something else then that something else is important to that something
- Therefore, nuclear fusion is important to star formation

Therefore, nuclear fusion is important to star formation
Question: Which of the following processes is an important part of star formation?
Context: - The formation of something is a kind of process 
- Nuclear fusion causes star formation 
- If something causes a process then that something is required for that process 
- If something requires something else then that something else is important to that something