【单选题】

All of the following are characteristics of a work package EXCEPT:
A．It is a deliverable or project work component at the lowest level of each branch of the work breakdown structur

B．It is a summary task at the top level of the WB
C．It includes the schedule activities required for completion of the deliverable or project work componen
D．It includes the schedule milestones required for completion of the deliverable or project work componen