Polarization features B and A plotted in the q–u plane. The upper panel shows the λ6355 Å line (Feature B) for all four epochs, plotted over 5840–6300 Å. The lower panel shows the feature A for all four epochs, plotted over 4500–5000 Å. The λ6355 Å line exhibits clear loops during the second and third epochs, while there is a suggestion of multiple loops during Epoch 1 for Feature A. The average error bar across each line is shown in the upper left of each panel.