Which group does the USPS serve under its universal service obligation?

The universal service obligation of the USPS is designed to ensure that postal services are accessible to all segments of the population, which includes the American people and businesses across the entire country. This principle reflects the USPS's mission to provide reliable and affordable mail service to every household and organization, regardless of location or the nature of the individual customer. This commitment helps maintain equitable access to communication for all citizens, making it a vital part of the nation's infrastructure.

The other options suggest a more limited scope of service. Focusing solely on government and commercial entities would exclude residential customers, while limiting service to international clients would negate the domestic obligations of the USPS. Similarly, emphasizing only rural populations overlooks the comprehensive service commitment to urban and suburban areas as well.