Children in Need Question

Yesterday on the Chris Moyles show, the all important, once in a life time question was announced. The competition launched by the BBC is to raise money for Children in Need by allowing 100 lucky competition winners and three members of the family the chance of a lifetime, as they will have the chance to tour the sets of Doctor Who and it's spin-offs and see some of the Doctor's deadliest enemies. The single question is as follows;

In the episode 'The Stolen Earth' where in space did the Daleks hide 27 planets?
A. The Horsehead Nebula
B. The Omega Spiral
C. The Medusa Cascade