As a link between different subgroups,Berta is a boundary spanner between different functional units.Berta is alone at the critical junction between these organizational networks,and serves an important role as a(n) ________.

A) information broker
B) advice tie
C) trust tie
D) leader

Berta's role as a boundary spanner suggests that she plays a critical role in exchanging information and knowledge between different subgroups. Therefore, the best choice for Berta's role is an "information broker." While Berta may also play a role as a "trust tie" or "advice tie," these roles are focused more on social connections and reputation rather than information exchange. Additionally, Berta's position as a boundary spanner does not necessarily imply that she is a leader in the traditional sense, as her role is primarily to facilitate communication between different groups rather than to provide direction or guidance.