Final answer:
An executive summary is included in a report to provide a concise overview, useful for complex information and for readers who may not have time to read the full document.
Step-by-step explanation:
An executive summary in a report is typically included when you need to provide a concise overview of the document's main points, which is especially useful in several scenarios. While the options given pertain to specific instances, the most universally applicable context is when the report contains complex information that readers, such as executives or stakeholders who may not have the time to read the entire document, need to understand quickly. Therefore, the correct answer to the question of when to include an executive summary in a report is not exclusively tied to one of the single options provided but rather can apply to multiple scenarios, such as when proposing a new idea or presenting to an audience who may benefit from a summary due to the length or complexity of the report, or when it is to be seen by people outside the organization who need to grasp the essence swiftly.