You are creating a model-driven app that uses standard tables for customer records. The company uses a Microsoft SQL Server-based on-premises system for its general ledger, accounts payable, and accounts receivable functions. The app must be able to view and perform calculations based on the discount agreements that the company has with its customers. What should you recommend?

A. Use a SQL gateway with virtual tables.

B. Use dual-write to map to the tables.

C. Use a REST API with a custom connector.

D. Implement Dynamics 365 Finance.