The correct answer is: Friction.
Friction is the force that opposes the relative motion of two objects or materials. In the context of labor and management, friction can refer to the conflict that arises between workers and their employers. This conflict can be caused by a variety of factors, such as differences in goals, values, and interests. Friction can lead to a number of problems, such as strikes, slowdowns, and sabotage. However, it can also be a source of creativity and innovation. When managed effectively, friction can help to improve communication and cooperation between workers and their employers.
The other options are not as accurate as friction. Controversy is a disagreement or argument about a particular issue. Association is a connection or relationship between two or more things. Competition is a rivalry between two or more people or groups in which each tries to gain an advantage over the other. Coordination is the act of organizing or managing things so that they work together effectively.