A business case exists to justify why the project should be done-what problem/opportunity it addresses and what benefits/value it provides relative to cost. In CompTIA Project+ objectives, the business case is part of discovery/concept and initiation, linked to business objectives and ROI, and is used to support approval decisions. The first, foundational element of that justification is clearly stating the problem being solved (or the opportunity being captured). () Option D best captures that intent: specify what problem is being solved by the project. Once the problem is defined, the business case typically expands to include expected benefits, costs, assumptions, constraints, and high-level risks-but those are supporting elements, not the primary objective.
Option A is more aligned to risk management artifacts (risk register, issue log). Option B (timeline and budget) is more aligned to the project plan and estimating/scheduling. Option C (specific tasks) aligns to a WBS or backlog planning. The sponsor is asking for the "why" and justification for investment before committing effort-so the business case objective is to articulate the problem and the value of solving it. ()