The correct answer is B. administrative.
Planning and control are administrative functions of an office because they are concerned with the organization and management of the office. Planning involves setting goals and objectives, and developing strategies to achieve those goals. Control involves monitoring progress and taking corrective action as needed.
The other options are incorrect because they do not accurately describe the nature of planning and control. Option A, informative, is incorrect because planning and control are not primarily concerned with providing information. Option C, public, is incorrect because planning and control are not primarily concerned with the public. Option D, private, is incorrect because planning and control are not primarily concerned with private individuals.
In addition to planning and control, other administrative functions of an office include organizing, staffing, directing, and coordinating.