Final answer:
Management accountants are responsible for preparing internal reports that review the actual impact of decisions, providing necessary financial analysis to inform business strategy.
Step-by-step explanation:
Internal reports that review the actual impact of decisions are typically prepared by management accountants. Management accountants are focused on analyzing business costs and operations to support internal decision-making. They analyze financial information to prepare reports that inform tactical and strategic decisions. While other roles such as department heads or controllers may be involved in the decision-making process or use these reports, it is management accountants who are generally tasked with preparing the detailed financial analysis necessary to review the impacts of decisions.