There Is a Close Relationship Between Sociology and the Other

There is a close relationship between sociology and the other social sciences. Given how much overlap there is, why does sociology still exist as a discipline?

A) All the other departments specialize in something, but sociology is a general field, bringing together the theories and findings from those other disciplines to produce a broad synthesis.
B) Only sociology worries about what will happen in the future.
C) Despite significant overlap, there is still a good deal of unique territory that only sociologists study.
D) Sociology departments exist as an academic tradition and would be difficult to disband.
E) Political science and economics departments are much more politically conservative, so sociology remains to provide a liberal counterbalance.