What project management plan is most likely to direct the quantitative risk analysis process for a project in a matrix environment?

A standalone risk analysis plan is not a recognized document in PMI methodology; all guidance for risk analysis approaches is contained within the risk management plan.

The staffing management plan addresses how human resources are acquired and managed on the project and does not direct risk analysis methodologies or techniques.

The human resource management plan governs how project team roles are defined and managed, not how quantitative risk analysis is conducted or what tools are used.

The risk management plan defines the methodology, tools, data sources, and approach to be used in all risk management processes including quantitative risk analysis. It provides guidance on which quantitative techniques to apply, required precision levels, and how results will be used - making it the primary directing document for this process regardless of whether the environment is a matrix organization or otherwise.