The Hawthorne and Likert Research

The Hawthorne and Likert research:

A) make it clear that authoritarian style leadership and supervision are not the most effective for long-term productivity.
B) found that that each level of management is a member of a multifunctional team that includes the next upward level.
C) showed that high pressure on subordinates through work standards was effective.
D) observed four approaches to supervision and leadership.