The following are the project tasks:
Task A (duration 4 days)
Task B (duration 3 days)
Task C (duration 4 days)
Task D (duration 2 days)
Task E (duration 3 days)
Task F (duration 4 days)
Task D and task F can not start until task C is completed.  Task A and task B can start at any time after task C starts, but must complete before the end of the project.  Task E can only starts after task D is completed.  During the execution of task B, which starts 1 day later after task C starts, exception happened which will cause a 2-day delay for task B、 What action should be taken to ensure the project can be completed on time?
A、Add more resources to task B
B、 No action is necessary
C、 Reassign resources to tasks on
D、 Add more resources to task D