The correct answer is C — Prepare the project plan . Product-based planning is central to preparing a reliable PRINCE2 plan. The project team begins by defining and analysing the products that must be delivered and then establishes their dependencies, activities, resource requirements, estimates, and sequence.

The workshop described in the scenario is explicitly breaking the site-preparation and foundation products into greater detail. That is a planning activity. The discovery that a more comprehensive environmental impact assessment will be necessary also affects the work required to produce the project’s products and potentially its schedule, resources, dependencies, and costs. Those implications should therefore be incorporated while preparing the project plan.

Option A concerns deciding how PRINCE2 and organizational project-management requirements will be adapted to the circumstances of LouisShopping. It is not the activity in which detailed product decomposition is performed. Option B concerns establishing the management approaches governing areas such as risk, issues, quality, commercial management, sustainability, and digital/data management. Option D uses the resulting estimates and other planning information to develop the project’s detailed justification, but the product-based planning workshop itself belongs to preparation of the project plan.

The sequence is important: detailed planning information can subsequently inform refinement of the full business case.

PRINCE2 7 reference topics: Initiating a project; prepare the project plan; plans practice; product-based planning; product analysis; estimates and dependencies.

===============