The correct option is Rule.

In management and organizational planning, different types of plans serve different purposes. Let's break down why a "Rule" is the correct answer:
1. Rule: A rule is a specific statement that details what must or must not be done in a given situation. It is rigid, allows no room for discretion, and demands absolute compliance. For example, "No smoking in the office" is a rule because it dictates a definite action to be taken (or not taken) without exception.
2. Policy: A policy is a general guide to thinking and decision-making. It provides a broad boundary or framework within which managers can use their discretion (e.g., "The company prefers promoting internal employees").
3. Strategy: A strategy is a comprehensive, long-term plan designed to achieve broad organizational goals in the face of environmental challenges and competition.
4. Procedure: A procedure is a chronological sequence of steps or routine steps to be followed to perform a specific activity (e.g., the steps to request annual leave).
Therefore, because a rule is a specific and definite directive requiring compliance without discretion, it is the plan that states a specific and definite action is to be taken or not to be taken.