Several comparisons of 2399 galaxies emitting He II with SnR > 5.5, measured and cataloged by SB12, and matched with the SDSS MPA-JHU catalog having S/N > 5 in all compared emission lines. SB12 SFGs and AGNs are represented by light blue rhombuses and violet triangles respectively. BPT SFGs are represented by a black cross. The X-ray-selected SFGs and AGNs (Section 3.1) are also shown with blue right-pointing and purple left-pointing triangles respectively. Top left: He II/Hβ over [N II]/Hα. The black curve represents the SB12 classification criterion separating AGN from SFGs. Top right: BPT [O III]/Hβ over [N II]/Hα diagram. The dashed black line shows the Kauffmann et al. (2003) classification criterion. Middle left: He II/Hβ as a function of EW_Hβ. Middle right: He II/Hβ as a function of metallicity. Bottom left: O32 as a function of EW_Hβ. The blue dashed line represents the best linear regression fit involving only BPT and SB12 SFGs. The black line represents a threshold above which only AGNs of our sample are located. Bottom right: He II/Hβ as a function of O32. The black dashed-dotted and blue dashed lines show the best linear regression fits involving solely SB12 AGNs or SFGs, respectively.