Q: What background question should I choose for my study?
The topic of the research is "split of university campuses and its effect on students."
The introduction of your research paper should provide the background of the study. While there are some essential bits of information that the background must include, there is no prescribed format for the manner in which it should be written. To begin with, you must set context by providing some background information on the field and the area of research. You can then gradually narrow it down to the topic at hand. Generally speaking, this is done through a detailed review of the existing literature on the topic.
I suggest you go through a few articles related to your topic and see how the background to the study has been dealt with. This will give you a better idea of how to go about writing the background to your own study.