Thesis writing must be concise, especially the abstract, introduction and conclusion, especially the abstract and conclusion can not be repeated. The periodical classification is roughly as follows (including some personal analysis and evaluation).

In fact, there are many unscientific places in CCF classification, and this classification is also the result of big-name games in China. Therefore, C is not necessarily worse than B. If you only want to vote for C and don't pursue quality, then you should also search the international reputation of this conference when choosing it. For example, PAKDD in the field of data mining is a C, but it has a very good reputation abroad.