Which statement about leadership is true?

Which statement about leadership is true?
a. Leadership can be exhibited by persons other than those formally designated as leaders by the organization.
b. The most effective leader will exhibit high consideration and high initiating structure in all leadership situations.
c. Initiating structure is a leadership trait.
d. There is a set of leadership traits that strongly and consistently predicts leader effectiveness across a broad range of situations.
e. A leader can be either high on initiating structure or high on consideration but not both.