What type of diagram visually indicates how a project schedule will unfold?

The Gantt chart is the correct choice for visually indicating how a project schedule will unfold. This type of diagram effectively displays the timeline of a project by illustrating the start and finish dates of various components and tasks within the project. It allows project managers and stakeholders to see the sequence of activities, the duration for which tasks are scheduled, and how different tasks overlap or depend on one another.

A Gantt chart can also highlight milestones and deliverables throughout the project timeline, making it easier to track progress and adjust plans as necessary. The visual nature of a Gantt chart helps to quickly convey information regarding the status of the project schedule, facilitating better communication among team members and stakeholders.

In contrast, while a network diagram is useful for establishing the relationships between tasks and understanding their dependencies, it does not provide an explicit view of the timeline in terms of task duration and scheduling. Fishbone diagrams are used primarily for cause-and-effect analysis and problem-solving rather than scheduling, while flowcharts focus on the steps in a process rather than the timeline of project planning. Therefore, the Gantt chart's specific focus on time makes it the most appropriate tool for illustrating how a project schedule will unfold.