Grant, a chief executive officer for more than two decades, has observed the rise of many people to positions of leadership in his company. In retrospect, he realizes that most of these people have exhibited a particular set of traits, including intelligence, ambition, a need for power, and an ability to adapt to changing circumstances. Grant's observations are consistent with the

a. great person theory.
b. interactions approach.
c. transactional approach.
d. contingency model.

a