Which of the following is a service offered by USPS.com?

The correct answer is zip code lookups, as this is a specific service provided by USPS.com. The United States Postal Service offers tools that allow users to find and verify zip codes for specific addresses. This feature is particularly useful for individuals and businesses needing accurate mailing information, facilitating the correct routing and delivery of mail.

The other options, such as online banking, travel booking, and online shopping, are not services provided by USPS.com. The Postal Service focuses on mailing and shipping services, along with tools that assist with those services, like zip code lookups, but it does not engage in banking, travel, or retail shopping activities. Understanding this helps reinforce the unique scope of USPS services and the tools available on their official website.