Establishing control accounts for the work packages and a unique identifier from a code of accounts finalizes the WBS.
This provides a structure for hierarchical summation of:
A. Schedule and requirements information
B. Cost and requirements information
C. Cost and resource information
D. Scope, budget and schedule information
Correct answer is D.
The WBS is finalized by establishing control accounts for the work packages and a unique identifier from a code of accounts.
This provides a management control point for integrated scope, schedule and cost information.
PMBOK Guide, page 161.