I know this chapter quiz is like a test, but I'm confused about what they are asking in this question, I like don't get it.

If you remember  we did line spectrum of H atom in chapter 7.
When electron jumps from high energy to low energy there is release of energy,
Different energy transitions feasible  are
3s....>2p
2p....>2s
3s....>2s
2p....>1s
3s....>1s
2s....>1s

ohh, wait I will go back to that and review my notes, I just remembered , thank you!