Which type of problem solving report should be used to study negative events that happened in the past so they are not repeated?

A) Justification
B) Due diligence
C) Market analysis
D) Failure analysis
E) Feasibility

Failure analysis is the type of problem solving report that should be used to study past negative events in order to identify the root cause of the problem and prevent it from happening again in the future. This type of report typically examines what went wrong, how it happened, and what could have been done differently to avoid the negative outcome.