Answer:
Answer explained below
Step-by-step explanation:
Coming through the ranks is important because it ensures the PM will have dealt with various levels of tasks and if the manager has dealt with tasks of each level throughout his or her career, then it will be easy for the project manager to decide on the holistic approach of the task and to solve the bottlenecks which may arise in all levels because of the handy experience this project manager would have.
It also ensures that a project manager who had come up through the ranks have more expertise and skills to implement a project most likely better than the other having lesser experience, even though the person possesses a greater educational background.
It is known that some of such tasks do not rely on only the higher education of the manager due to the nature of the jobs, but also level of experience.