In MRP, system nervousness is caused by

A) management's attempt to continually respond to minor changes in production requirements.
B) the use of the lot-for-lot approach.
C) management's marking part of the master production schedule as "not to be rescheduled."
D) the use of phantom bills of material.
E) management's attempt to evaluate alternative plans before making a decision.

System nervousness in MRP is caused by management's attempt to continually respond to minor changes in production requirements, which creates instability and variability in the system. By constantly adjusting the plan in response to small changes, the system becomes more sensitive to fluctuations and can result in increased costs, reduced efficiency, and decreased productivity. A better approach is to establish stable production schedules and only make changes when there are significant shifts in demand or capacity.