Pe /z effect refers to:

The Pelz effect says that when a supervisor is supportive and subordinates have adequate upward influence, meaning they can actually shape decisions and be heard by the boss, productivity and job satisfaction rise together. Donald Pelz's study of research scientists in the early 1950s found that a supportive supervisor alone was not enough. The group that could also influence the supervisor performed better.

Why D is correct: The two ingredients are supervisor supportiveness and adequate upward influence. Both must be present.

• A is wrong because the second factor is upward influence, not lateral (peer-to-peer) influence.
• B is wrong because the supportiveness must come from the supervisor, not from the subordinate's demand.
• C is wrong on two counts: it names the supervisor's demand instead of supportiveness, and low upward influence is the opposite of what the effect needs.

Core concept: leadership style and two-way influence. It links to the Mains ethics and governance theme of participative administration: a supportive officer who also listens to the staff gets better output than one who only gives orders.

Trap: Candidates mix up upward and lateral influence, or treat supportiveness as a subordinate's demand. Read the exact wording of each option.