The correct answer to this open question is the following.
Lin manages a team of business consultants. During a meeting, Jack, a senior business consultant, puts forth a new idea to tackle with the insufficient infrastructure at the workplace. Lin applauded Jack on his effort to come up with a solution. In this scenario, Lin performs the role of a supporter.
Leaders are effective when they are the first one to exemplify the kind of roles and behaviors they want in their team.
Leadership is the art to inspire other people to do what they need to do in order to get what they and the organization want to accomplish. The important thing is the leader setting the example of the conducts that he demands in other people. The leader "talk his talk and walk his walk." People in an organization have to see that leaders are congruent. So in this case, when Jack takes the role of supporter, he shows that being supportive is a good characteristic that is valued in the organization and he is the first one to assume that role.