_______________ in management is concerned with doing the right task, completing activities and achieving goals.

The correct option is Effectiveness.

In the study of management, effectiveness refers to the completion of activities so that organizational goals are attained. It is often summarized as "doing the right things"—which involves choosing the correct goals and ensuring that the necessary tasks are successfully completed to achieve the desired outcomes.

To clarify the distinction:
1. Effectiveness is about the end result: doing the right task, completing activities, and achieving organizational objectives.
2. Efficiency is about the process and resources: doing things right, minimizing costs, and maximizing output relative to inputs.

Since the question focuses on doing the right task, completing activities, and achieving goals, the correct term is Effectiveness.