The flow of demand information in a supply chain starts with the customer, who initiates demand for products or services. This demand information then moves upstream to the manufacturer, who needs to know the customer demand to plan production and control inventory. From the manufacturer, the demand information continues upstream to the supplier, who provides the raw materials or components needed for manufacturing. Therefore, the complete flow of demand information is accurately described as moving from the customer to the supplier.

Reference

Chopra, S., & Meindl, P. (2016). Supply Chain Management: Strategy, Planning, and Operation. Pearson.

Simchi-Levi, D., Kaminsky, P., & Simchi-Levi, E. (2008). Designing and Managing the Supply Chain: Concepts, Strategies, and Case Studies. McGraw-Hill.