I'm certain you're right, CT, and that the answer required will indeed be 'southern'. However, I believe there is an 'official' line dividing eastern and western hemispheres...ie the 0 degrees line of latitude and its continuation as the 180 degrees line. The Greenwich Meridian is as much a dividing line as the equator is in terms of earth measurement. Even the earth's days are dictated by it.
Granted, Loosehead, there is an infinite number of possible hemispheres, but only two labelled 'Zero'...ie the two baselines!
Those are the reasons why I opened my first answer with the underlined word 'and'.