Final answer:
The phase that includes determining tactical direction, specific resources, and support requirements for strategies and tactics is the 'Develop the Plan' phase.
Step-by-step explanation:
The planning phase that involves determining the tactical direction and the specific resources, reserves, and support requirements for implementing the selected strategies and tactics for the operational period is known as C. Develop the Plan. During this phase, planners detail the tactics necessary to achieve the incident objectives, specify resource types and quantities, define timelines, and determine appropriate reserve resources. They also identify support requirements for the operational strategies to be effective.
Plan D, as referenced in a different context, reflected a strategic military approach rather than a tactical one, and would not be conflated with the planning phase of incident management. The process phases such as Preparatory, Implementation and Learning, Program Evaluation, and Development of Lessons Learned, represent a broader sequence of steps that could encompass multiple planning cycles over time.