Populated :/ right? Love ya much Fam ;)
I think you might mean International Conference on Population and Development
This conference focused on many issues, such as introduction, reproduction and hearth. From the options provided the closest is "overpopulation" - c. The other options were not covered in the conference.
I believe the answer would be, "Posture".
This represents the source of research ideas called classroom lecture.
There are several sources which can inspire and help someone to develop a research question. Some of them are theory, everyday occurrence, serendipity and past research. In this case, Whitney was taught about the bystander effect in her social psychology course and she was inspired to undertake an undergraduate research project on this subject.