In the Context of Scientific Management, Which of the Following

In the context of scientific management, which of the following is true of Frederick Taylor's contributions?

A) Taylor believed that supervisors would be motivated to provide training to underperforming workers.
B) Taylor created the Gantt chart, which helps managers plan projects by task and time to complete those tasks.
C) Taylor developed a system to lower costs and increase worker productivity by showing how employees could work smarter, not harder.
D) Taylor eventually focused less on the technical and more on the human side of management.
E) Taylor advocated the use of the differential piecerate system.