The research showing that your idea is something people will actually buy can support your business plan primarily by communicating how you’ll ensure your product will sell. This involves understanding market demand, consumer behavior, and how your product meets the needs or wants of your target audience.
While the other options—such as production costs, profit margins, and competitor analysis—are important components of a business plan, demonstrating that there is a viable market for your product is critical to ensuring potential investors or stakeholders are confident in your product's potential success. Market research helps in validating your product's fit within the marketplace and provides evidence that supports sales forecasts and marketing strategies.