What makes the managerial task of executing strategy so challenging and demanding is A. the trial-and-error experimentation that is required to come up with a workable organizational structure that can adapt to the mature stages of the industry life cycle. B. the demanding people-management skills required, the resistance to change that has to be overcome, and the perseverance necessary to get a variety of initiatives launched and kept moving along. C. the time and effort it takes to build core competencies and a robust code of ethics. D. the time, training, and creative effort it takes to empower employees and teach them to communicate with their customers. E. the supervisory requirements associated with getting company personnel to do benchmarking.