How does the scope of planning vary among different levels of management and departments?

It differs at different levels and among different departments

The correct answer is option 3 i.e. It differs at different levels and among different departments.

Planning is required at all levels of management as well as in all departments of the organisation. It is not an exclusive function of top management nor of any particular department. But the scope of planning differs at different levels and among different departments. For example, the top management undertakes planning for the organisation as a whole. Middle management does the departmental planning. At the lowest level, day-to-day operational planning is done by supervisors.