A work breakdown structure is most useful for?

Break down of work is useful to identify required tasks and then to assess the tasks which are urgent and important.In case of time pressure it also helps to identify those tasks which can be delayed.So in my opinion E is the answer.It can also help in estimating cost of potential delays.Identification of tasks is essential but it may of no value unless these tasks are prioritise.

Out of the given options ,option B is more appropriate.

Thanks for the invitation:

I think the order for most useful goes in these order 

First         (B)

Second   (D)

Third        (C)

Fourth      (A)

Inmy opinion, Option E is better choice

there is a time when all plant will shut down all delays were reported and corrected during this agreed upon period so it is really option a for determining potential delays and correct them as well

Thank you for invitation. I seem option D-identifying individual tasks for a project is good answer.

My answer is for option (D)