Final answer:
The correct answer is: d. It may not have a predecessor(s) or a successor(s). Within project management, activities in a project schedule must have predecessors, successors, or both. An activity without either is not possible, as it does not fit within a project sequence.
Step-by-step explanation:
The question provided relates to the concepts of project management and activity scheduling. Specifically, it discusses conditions that can be present for an activity within a project timeline. Let's analyze the options given:
- An activity may have a predecessor(s) but no successor(s). This represents an activity that follows others, but is the last one in the project sequence.
- An activity may have a successor(s) but no predecessor(s). This could be the first activity of a project, initiating the sequence.
- An activity may have both predecessor(s) and successor(s). Most activities in a project will fall into this category, lying in the middle of the project sequence.
- An activity may not have a predecessor(s) or a successor(s). This condition is not possible in a project as every activity is part of a sequence, even if it's the first or last activity; it still would have a successor or predecessor respectively.