The correct answer is: A. Efficient & effective.
Successful managers are efficient and effective in their work. They are able to get things done quickly and correctly. They are also able to make good decisions that benefit the company.
Option B is incorrect because strictness is not always necessary for success. In fact, some managers find that being too strict can actually lead to decreased productivity and morale.
Option C is incorrect because policy makers are not necessarily successful managers. In fact, some policy makers are very good at making policies, but they may not be very good at managing people.
Option D is incorrect because decision makers are not necessarily successful managers. In fact, some decision makers are very good at making decisions, but they may not be very good at managing people.
In conclusion, successful managers are efficient and effective in their work. They are able to get things done quickly and correctly. They are also able to make good decisions that benefit the company.