An engineer must design a routing solution for a company that is single-homed to an ISP. The company's goal is to run BGP between the CE and the PE devices. To support running BGP, the company…

The customer announcing a default route to the ISP is typically incorrect; the customer usually receives a default route from the ISP to reach the internet, rather than advertising one.

This choice is functionally identical to option D, which is the correct action.

The ISP does not announce the customer's public IP subnet to the customer; the customer announces it to the ISP, and the ISP then advertises it to the broader internet.

When a company owns a public AS number and IP subnet and establishes a BGP peering with its ISP, the customer (CE router) is responsible for advertising its specific public IP subnet to the ISP (PE router). This ensures that the ISP can advertise these prefixes to the global internet, making the customer's network reachable from external destinations.