The correct answer is: A. delegation.
Delegation is the process of assigning tasks and responsibilities to others. It is a key management skill that allows managers to multiply themselves and get more done. When managers delegate effectively, they can free up their time to focus on more important tasks, and they can also develop their team members' skills and abilities.
Coordination is the process of ensuring that different parts of an organization work together effectively. It is important for managers to coordinate the work of their team members so that they are all working towards the same goals.
Cooperation is the act of working together towards a common goal. It is important for managers to create a cooperative environment in their team so that team members are willing to help each other out.
Influence is the ability to get others to do what you want them to do. It is an important skill for managers to have, as they often need to influence their team members, their superiors, and other stakeholders.
Delegation is the most important of these four skills because it allows managers to multiply themselves and get more done. When managers delegate effectively, they can free up their time to focus on more important tasks, and they can also develop their team members' skills and abilities.