Final answer:
The Gantt Chart is the tool most likely to be used in project time management, as it visually represents project timelines and tasks, aiding in planning and tracking progress.
Step-by-step explanation:
In project time management, the most likely tool to be used is a c) Gantt Chart. A Gantt Chart provides a visual timeline for project tasks and is instrumental in planning, coordinating, and tracking specific tasks in a project. It allows project managers and team members to see the start and end dates of project elements, as well as monitor the progress of the project.
Other tools listed, such as Payback analysis, which is typically used in financial decision making, Impact matrices for prioritizing risks or changes, and Fishbone diagrams (also known as Ishikawa or cause and effect diagrams), used for identifying root causes of problems, are not directly related to time management in the context of project management.