The correct answer is: D. All the above.
A bar chart is a chart with rectangular bars with lengths proportional to the values that they represent. Bar charts are used to compare different categories of data.
A Gantt chart is a type of bar chart that illustrates a project schedule. Gantt charts show the start and finish dates of the various tasks in a project, as well as the dependencies between them.
A modified milestone chart is a type of bar chart that shows the start and finish dates of the major milestones in a project. Milestone charts are used to track the progress of a project and to identify any potential problems.
All three of these charts are used to represent time and progress in a construction project.