The following table is an activity list that includes the duration and predecessor for a series of project activities. What is the duration of the critical path? | Activity | Duration | Predecessor | |---|---:|---| | A | 2 | Start | | B | 4 | A, E | | C | 6 | A | | D | 3 | B, C | | E | 7 | Start | | F | 2 | E | | End | - | D, F |