Final answer:
The key activity performed by operations managers focused on assigning work tasks and responsibilities is Job Design. It involves making decisions between the reduction of transaction costs or conformity costs to manage the workforce effectively.
Step-by-step explanation:
The key activity performed by operations managers that involves deciding the best way to assign people to work tasks and responsibilities is C. Job design. When dealing with the organization and coordination of work, decisions must be made to effectively delegate tasks and manage teams. These choices often come down to a trade-off between different costs associated with the methods of coordination.
On one hand, empowering a single person or a small group with decision-making authority (Task delegation) can lower transaction costs, since it simplifies communication and decision-making processes. However, this can lead to higher conformity costs as it might suppress individual initiative and creativity. On the other hand, a more collective approach to decision-making often comes with reduced conformity costs, fostering diversity in solutions and ideas, but can significantly increase transaction costs due to more complex decision-making processes involving many individuals.
Thus, job design deals with balancing these costs to create an effective organizational structure that aligns with the company's goals and strategies, ensuring that the workforce is utilized as efficiently as possible.