You are working with a team to estimate the costs of each activity and the total project costs. You are using a document that contains information on the time is required for each tasks and the preliminary responsibility for the tasks. Which of the following documents would you primarily refer to for this purpose? Group of answer choices Resource breakdown structure Organizational breakdown structure Work breakdown structure Risk breakdown structureFill in the blank. ____________ diagrams are generally more difficult to construct because they may require the use of "dummy" arrows to show relationships between activities that share an end event and to preserve precedence relationships. Group of answer choices Activity-on-the-node Activity-on-the-arc PERT CPMFill in the blank. ____________ diagrams are generally more difficult to construct because they may require the use of "dummy" arrows to show relationships between activities that share an end event and to preserve precedence relationships. Group of answer choices Activity-on-the-node Activity-on-the-arc PERT CPM