Answer D
An IFR Pickup essentially allows entry into Class E airspace whilst awaiting an airways clearance (due ATS/ATC workload etc)
Pilots of IFR aircraft accept responsibility in VMC for separation whilst continuing to receive TI and FIS. ATC will issue a clearance(eventually) and provide a full separation service once it is practical to do so.
If a higher class of airspace is rqd then a clearance will be needed as per usual
IFR Pickup is a good resource. Forget the AIP/Jepp reference sorry.
Very easy procedure..just remember its essentially a pending clearance.
Hope this helps