Much like the Campeonato Brasileiro, groups in the reduced series, including B and C, is usually promoted to the best division annually. In the case of Italy, just the best 3 groups in Serie B are promoted to Serie A (in Brazil, advertising happens for 4 groups in Serie B). https://ty-le-keo-nha-cai05789.glifeblog.com/36407156/facts-about-what-is-serie-a-revealed