Final answer:
Only a subtask can have a remaining work or duration value, as it represents a specific portion of a project, unlike summary tasks, milestones, or inactive tasks(option c).
Step-by-step explanation:
Only a subtask can have a remaining work or duration value(option c).
In project management, a subtask represents a portion of a larger task or project and can have its own specific duration or amount of work needed for completion. On the other hand, a summary task aggregates the information from its subtasks and does not itself have a duration value that can be 'remaining' since it is simply a roll-up of its subtasks. Milestones are typically set to have zero duration because they signify the achievement of a significant point or event in a project, and inactive tasks are tasks that are not currently active in the project schedule.