Which of lettered spectral lines corresponds to transition

Electron Transitions and Spectral Lines Conceptual Question

The spectrum of a hypothetical atom is shown in the figure.

Three distinct spectral series are shown, with the center series corresponding to transitions to a final state of nf=3. The indicated spectral line corresponds to the transition from an initial state of ni=5 to the final state nf=3.

Part A. Which of the lettered spectral lines corresponds to the transition from ni=6 to nf=3? You did not open hints for this part.

Part B. Which of the lettered spectral lines corresponds to the transition from ni=5 to nf=4? You did not open hints for this part.

Part C. Which of the lettered spectral lines corresponds to the transition from ni=5 to nf=2?