When slack of an activity is negative

A)
the activity is critical and any delay in its performance will delay the completion of whole project
B)
it represents a situation where extra resources are available and the completion of project is not delayed
C)
it represents that a programme falls behind schedule and additional resources are required to complete the project in time
D)
All of the above

Correct Answer : Option (C) :   it represents that a programme falls behind schedule and additional resources are required to complete the project in time