Final answer:
An ERP, or Enterprise Resource Planning system, is the supply chain information system used at the strategic level for internal supply chain management. It integrates various internal business functions and manages external connections.
Step-by-step explanation:
A supply chain information system that is used in the internal supply chain at the strategic level is C.an ERP. ERP stands for Enterprise Resource Planning, and it integrates various functions within an organization, such as procurement, production, distribution, and finance. ERP systems facilitate the flow of information between all business functions inside the organization and manage the connections to outside stakeholders.
An ERP provides a central repository for information that can be used to manage all areas of a business's operations. This makes them different from other systems such as Customer Relationship Management (CRM), Decision Support Systems (DSS), and Supplier Relationship Management (SRM) systems, which tend to focus on specific areas such as customer, decision-making, and supplier management, respectively.