A software development project has 9 activities. The activities' durations in weeks and predecessors are as follows: Activity Predecessors Duration A 6 B A 4 A A 5 D B 5 E B.C 5 F E 2 (1) C,D N H F G 5 E 2 What is the project duration? The critical path is: OA-B-D-G-H OA-C-G-H OA-C-E-1 OA-C-E-F-H OA-B-E-F-H What is the free float of activity B