Final answer:
The Marketing function in a business uses sales forecasting to plan new products, by analyzing market trends and customer demands to predict future sales and inform product development strategies.
Step-by-step explanation:
The function in a business organization that uses sales forecasting to plan new products is Marketing (Option A). Sales forecasting is a key activity within marketing, where predicted future sales are used to make strategic decisions about the products and services a company should offer. This involves analyzing market trends, customer demands, and overall industry changes to make educated guesses about future sales. The insights gained from sales forecasting are crucial for product development, promotional strategies, and aligning with the company's overall business objectives.