Order-filling activity in the physical system is triggered by the A. manufacturing information system B. order entry subsystem C. billing subsystem D. accounts receivable subsystem E. None of the above

The correct answer is: B. order entry subsystem.

The order entry subsystem is responsible for receiving and processing customer orders. Once an order is received, it is entered into the order entry system and the order fulfillment process begins. The order fulfillment process involves picking, packing, and shipping the order to the customer.

The manufacturing information system is responsible for managing the production process. The billing subsystem is responsible for generating invoices and collecting payments from customers. The accounts receivable subsystem is responsible for managing customer accounts and tracking outstanding invoices.

None of the other options are responsible for triggering order-filling activity in the physical system.