Consider the following statements with respect to PERT:
1. It consists of activities with uncertain time phases
2. This is evolved from Gantt chart.
3. Total slack along the critical path is not zero
4. There can be more than one critical path in PERT network
5. It is similar to electrical network.
Which of the statements given above are correct?
(a) 1, 2 and 5 (b) 1, 3 and 5
(c) 2, 4 and 5 (d) 1, 2 and 4