How many subjects are required for upgrading from C1 to B2 license?

[OAlivia]

C1 upgrading to B2 requires passing four subjects, starting from Subject 1, including Subject 1, Subject 2, Subject 3, and Subject 4. The examination process for upgrading from a C1 driver's license to a B2 driver's license: Upgrading from C1 to B2 requires retaking the exams starting from Subject 1. The contents of Subject 1, Subject 3, and Subject 4 remain unchanged, which are the theoretical test, road test, and safe driving civilization test, respectively. As for Subject 2, it includes stake test, hill start, parallel parking, single-plank bridge, curve driving, right-angle turn, passing through width-restricted gate, passing through continuous obstacles, bumpy road driving, narrow road U-turn, as well as simulated highway driving, continuous sharp turns on mountain roads, tunnel, rain (fog) weather, slippery road, and emergency handling.