Which of the Following Statements Is True of the Hawthorne

Which of the following statements is true of the Hawthorne studies?

A) The studies indicate that management style is a primary factor in increasing employees' productivity.
B) The studies suggest that workers tend to work harder when they are aware that their performance is being studied.
C) The studies strongly support management's obsession with efficiency and its effect on the human side of business.
D) The studies focus on the impact of mechanization on labor and productivity.