Which can be termed as disadvantage of PERT?

(A) Compels managers to plan their projects critically in considerable detail from beginning to the end and analyse all factors affecting the progress of the plan

(B) Provides management a tool for forecasting the impact of schedule changes. The likely probable spots are located early enough to take preventive measures or corrective actions.

(C) A considerable amount of data may be presented in a precise manner.

(D) The costs may be higher than the conventional methods of planning and as it needs a high degree of planning skill and minute details resulting in rise in time and manpower resources.