选择题：110The reason that cost management is so difficult in project management is that: A.Projec

110 The reason that cost management is so difficult in project management is that:

A. Projects by definition and nature are non-recurring events and are therefore difficult to predict.

B. There are no tools for identifying project tasks.

C. Project managers do not care about tracking costs, as only schedules are important to all project managers.

D. A and B only

E. B and C only