This is the head office.
B Chongqing Iron and Steel Co., Ltd. This is a wholly-owned subsidiary of the head office.
Popular means that b is a part of a.
The listed company is B Chongqing Iron and Steel Co., Ltd..
What people in the stock market say is that it must be a joint-stock company.
Not necessarily in life. Both are possible.
You can't judge whether it is good or bad. Actually, the two are family.