Leadership is the action of leading people in an organization towards achieving goals. Leaders do this by influencing employee behaviors in several ways. A leader sets a clear vision for the organization, motivates employees, guides employees through the work process, and builds morale. Answer the following questions in detail with examples as applicable :

a) What are the different leadership roles? Explain each of them provides examples of leaders in each role. 

b) Discuss the characteristics of the ‘Great Man Theory and ‘Blake -Mouton Leadership theory.