What are two types of investigation?

• A. Initial and final
• B. Preliminary and secondary
• C. Formal and informal
• D. Primary and secondary

Answer: (B)

In this area, investigations are understood to happen in two stages that control how deeply you probe after an incident. Start with a preliminary investigation to quickly establish what happened, collect essential facts, identify witnesses, and preserve evidence. It’s fast, scoped, and aimed at deciding whether a fuller look is needed. If more detail is required, you move into a secondary investigation, which is more thorough and structured. It digs into root causes, contributing factors, and safety shortfalls, and it produces formal findings and corrective actions.

That’s why the two types described are the best fit: one is the quick, initial look, and the other is the deeper follow-up. The other options describe different notions (start vs. end, formal vs. informal, or a hierarchy) that don’t match the common two-stage approach used in incident investigations.