You have an interest in sociology, thats nice. But we must opt subjects with scope in different sectors. Sociology as a subject is fine, but have u any interest in field work. Do u think that it would be suitable for you in future? Morover try to opt subjects in graduation that have great space in CSS, so that u would have an edge after doing master in ur subjects. A person having master degree in sociology can guide you better. He/she would provide the detail of scope as well as space of this subject in css. otherwise as a single subject it has 100 marks only, so what about the remaining 500.
So, I suggest you to think again over it.