Left panel: the sini–flaring activity relationship for FC stars (T_eff < 3200 K). The filled circles denote flaring stars in our sample, and the filled stars denote the four stars in E. Ilin et al. (2021), where high-latitude flares have been identified. All stars are fast rotators and in the C region. Right panel: the S_ph–flaring activity relationship for FC stars in the C region. The Pearson correlation coefficient is r ≈ 0.23.