Final answer:
Managing refers to the coordination and oversight of tasks to ensure efficiency and effectiveness in achieving organizational objectives.
Step-by-step explanation:
The activity that involves ensuring that work activities are completed efficiently and effectively by the people responsible for doing them is Managing (option B).
Managing encompasses the coordination and oversight of tasks and resources in an organization to achieve defined objectives. Managers ensure that their team's work aligns with the company's goals and that resources are used effectively to produce the desired outcomes.