Final answer:
The first step in developing an action plan is to clarify the goal, as it defines the direction and purpose of all following actions.
Step-by-step explanation:
The first thing a student should do when developing an action plan is clarify the goal. This step is crucial because it lays the foundation for all subsequent steps in the planning process. By clarifying the goal, you ensure that each action you take is aligned with your main objective. Without a clear goal, any list of actions, priorities, or organization would lack direction and purpose. Once the goal is defined, it becomes much easier to organize a list of action items, prioritize essential actions, and write a comprehensive list of actions. Therefore, D. clarify the goal is the best answer from the choices provided.