Consider the following statements.
1. In PERT, it is assumed that the activity times follow the beta distribution.
2. In CPM, two time and cost estimates are made for each activity, which are called the optimistic and pessimistic estimates.
3. Time is the only variable used in PERT.
4. While in PERT the emphasise is on event, in CPM the emphasise is on activity.

A. While 1 and 2 are false, 3 and 4 are true

B. 1, 3 and 4 are true

C. All of the aboveare false

D. All of the above are true

Answer: Option B