Which of the following documents should be stamped or sealed by a qualified professional?

The professional stamp or seal is a legal mark of reliance. When a regulated professional (such as a P.Tech., or an engineer) affixes their seal to a document, they are publicly certifying that the work was prepared by them or under their direct supervision, that it meets all applicable codes and technical standards, and that they accept full professional and legal responsibility for its contents. Consequently, a seal must only be applied to final documents—such as final drawings, specifications, technical plans, and formal engineering reports—that are intended to be relied upon by others (clients, contractors, or municipalities) for construction, manufacturing, or significant decision-making. Seals should not be applied to preliminary drafts, internal memos, or non-technical business documents (Option A), nor is their use merely "recommended" (Option D); it is legally mandated for final technical works. Furthermore, their use is not strictly limited to public safety projects (Option C), but to any finalized technical design within the professional's authorized scope of practice.