The correct answer is A . To avoid repeating mistakes from previous projects, the organization and project team should utilize lessons learned from previous, relevant projects. Lessons learned capture practical knowledge about what went well, what went wrong, what assumptions failed, what risks occurred, which controls were effective, which stakeholder issues emerged, and what should be improved in future projects. Applying lessons learned strengthens planning, governance, risk management, estimation, stakeholder engagement, procurement, quality control, and delivery execution. Hiring subject-matter experts may be useful in some circumstances, especially where specialist knowledge is required, but it does not directly replace the value of organizational learning. Experts can still repeat past mistakes if the project does not actively review and apply prior lessons. The duplicate subject-matter expert options do not change the correct answer because the principle being tested is knowledge reuse. ISO 21502-aligned practice treats lessons learned as an important input for improving current and future project performance. The uploaded source question specifically asks what should be considered to avoid repetition of previous mistakes and identifies lessons learned from previous, relevant projects as the proper response.

Reference topics: lessons learned, organizational knowledge, continuous improvement, previous projects, project planning, risk avoidance.