In a pert network, non-critical activities that have little slack need to be monitored closely
a. because pert treats all activities as equally important
b. because near-critical paths could become critical paths with small delays in these activities
c. because slack is undesirable and needs to be eliminated
d. because they are causing the entire project to be delayed e. because they have a high risk of not being completed

b)because near-critical paths could become critical paths with small delays in these activities

Explanation: Program evaluation and review technique(PERT) technique is used for management of the project .The organizing, maintenance,coordination of any task is done by this chart. The non-critical activities need to be observed carefully because they may create near-critical methods which can lead to complexity.

Other options are incorrect because not all activities are equally rather monitoring is done to avoid errors and slack can occur at any path . Small delays can be caused but not complete project can get delayed and there can be risk of complexity rather than being uncompleted.Thus, the correct option is option(b).