There can be many ways to compare the two topics, but here is a comparison that I think is most suitable to select one of the topics for the css exam.

1. Anthropology is easier as it is more generic and open in terms of writing an answer, whereas sociology can get a bit tricky once a reference is drawn to the contemporary situation of the country and the exam wants you to draw the relation between the theory and existing situations.

2. Anthropology course is really short and simple, with a few reference books required.

In order to draw a comparison yourself try going over the past papers of the past 5 years of the two subjects and you will be able to make a solid decision to go with anthropology instead of sociology.

Well that was my analysis, maybe you will have a different pov once you go over the syllabus and the past papers.

Good day.