Ok thank you, I understood.
Could you gently answer to my two questions (expecially the first one, that is if there is a League B or not)?
No. The competition is named after 资格赛 in Chinese.
In order to tell you simply, I used "Challenge Match", "Challenge League", "Challenge Games", "Qualifiers" and so on.
For example, in the time when national teams are playing all around the world, the matches of Chinese Province Teams are names after 全国排球锦标赛 (National Volleyball Championships). However, you could just think it to be warm-up matches with some money as the prize.
warm-up matches are named after "championships". What do you think?