Hey!
These four theories relates pretty much to anything in the SAC core topic, but mostly is explored in your focus study for the core. Usually schools do China for Social and Cultural Continuity and Change. Any of the social theories can be applied for China, however the conflict theory relates the most to China.
Depending on your electives, the four theories can be used in those areas. Unless your teacher introduces a new theory that is more applicable and accurate.
So far, social theories usually pop up in Section 1 (core). For this year's HSC exam, they asked how one social theory can explain change in one aspect of your chosen country. They usually don't ask for social theories in Section 2, but it looks better to include one as this demonstrates your capacity to relate your electives to a legitimate social theory rather than making random predictions without backing it up with facts.
Hope this helps
