To generate an effective monthly summary with Copilot in Excel, Microsoft prompting guidance emphasizes two core elements: clear intent and expected output structure. First, you should state the goal explicitly---such as ''summarize total sales by month based on OrderDate and Amount, and highlight month-over-month changes.'' This directs Copilot to the correct aggregation and analysis behavior (Option D).

Second, specifying the desired format improves usability and reduces ambiguity. For example, requesting ''a table with Month, Total Sales, Number of Orders, and Average Order Value'' or ''a bulleted executive summary plus a small summary table'' ensures Copilot returns results in a format you can immediately use (Option A).

A specific cell range (Option B) is usually unnecessary when the data is already in a recognized Excel table, because Copilot can work from the table context. The workbook file name (Option C) does not help analysis. Providing a formula (Option E) is not required because Copilot can compute monthly totals; formulas are optional if you want a specific calculation method, but they are not the best prompt ingredients for an effective summary.