The question in full:
Now that you have a better understanding of research methods, create and write one research question that could be answered by each of the following methods and explain why it is answered by each method: correlational research, experimental research, and case study.
CLARIFICATION: The instructions call for ONE reseach question and an explanation of how that ONE question could be answered using the three different research methods: correlational research, experimental research, and case study.
The attached file is just the textbook chapter describing research study methods. Any decent psychology student should know that stuff already.