The "Electric Distribution Network Construction" project has the activity network diagram and estimated durations as shown below: Project: Electric Distribution Network Construction Duration [weeks Most Activity Optimistic Likely Pessimistic 12 30 18 10 18 D Useful Formulas: most optimistic - most likely 1 +41 +1 (1, -12) most pessimistic 6 6 expected duration vanance Using the PERT method, indicate the critical path: C A-B-C-F A-D-E-F A-B-E-F O A-D-C-F