The correct answer is: D. All of the above.

A. The aim of organizing is to help the individuals to works for a common goal.

This is true because organizing is the process of creating a structure for a group of people to work together effectively. It involves identifying the tasks that need to be done, grouping them into related areas, and assigning them to individuals or teams. Organizing also involves establishing lines of communication and authority, and developing procedures for coordinating the work of different individuals and teams.

B. Unity of command is a principle of planning.

This is true because unity of command means that each individual should have only one supervisor. This helps to ensure that orders are clear and that there is no confusion about who is responsible for what. Unity of command also helps to prevent conflict and duplication of effort.

C. The basis of staffing is a principle of planning.

This is true because staffing is the process of filling the positions in an organization with qualified people. It involves identifying the skills and abilities that are needed for each position, and then recruiting and selecting the best candidates. Staffing also involves orienting and training new employees, and evaluating their performance.

All of these principles are important for effective planning. By following these principles, organizations can create a structure that will help them to achieve their goals.