Pessimistic time refers to:

A) the maximum period of time for an activity to be completed.
B) the minimum period of time for an activity to be completed.
C) the planner's "best guess" of the amount of time the activity actually will require for completion.
D) the maximum period of time for an entire project to be completed.
E) the average period of time for an activity to be completed.

A
Explanation: A) When scheduling, if one considers that a task will take the maximum time this is pessimistic time.