Final answer:
A supervisor who consults subordinates in decision-making through mutual consent and discussion is exercising Democratic leadership, the correct answer being option a) Democratic.
Step-by-step explanation:
When a supervisor acts according to mutual consent and discussion, consulting subordinates in the decision-making process, this is known as participative or consultative supervision. Based on the options provided, the correct answer is a) Democratic. Democratic leadership encourages group participation in all decision making and aims to build consensus before settling on a course of action. This approach to leadership is contrasted by two other styles: autocratic or authoritarian, where the leader makes decisions unilaterally, and laissez-faire, where the leader takes a hands-off approach and allows group members to self-manage and make their own decisions.