Gantt charts were used to plan and coordinate construction steps on this large U.S. infrastructure project.

• A. Hoover Dam
• B. Gantt chart
• C. Early Soviet Union
• D. Kanban

Answer: (A)

Gantt charts map out tasks, durations, and dependencies so a large project can be planned and tracked over time. Hoover Dam, built in the 1930s on the Arizona–Nevada border, was a massive U.S. infrastructure effort that required coordinating thousands of workers and many interdependent construction steps—excavation, foundations, dam structure, formwork, concrete pours, and the power plant. A Gantt-style schedule would let managers sequence these activities, allocate resources, and monitor progress against the timeline, helping keep the project moving despite its scale. Kanban is a flow-management method used mainly in manufacturing and software; the Early Soviet Union is a historical period, not a specific construction project; the option naming the chart itself is just the tool, not the project.