ZIP codes were introduced by the U$.$S$.$ Postal Service on July $1,1963.$ The term ZIP, which stands for Zone Improvement Plan. suggests that the mail will "zip along" more efficiently if postal customers use the code. The basic code consists of five digits. In $1983$ the ZIP $44$ code was introduced to direct mail to a more specific location within a ZIP code. The ZIP $+4$ code added a hyphen and four digits to the basic code.

A student reads the above passage in an encyclopedia and wants to learn more about the U$.$S$.$ Postal Service. In which of the following magazine articles would the student most likely find relevant information about zip codes?

"Postmasters General of the U$.$S$.$ Postal Service"

"Postal Code Zones of the US$.$ Postal Service"

"Postal Service in the Age of Digital Communication"

"The Pony Express: Postal Service of the American Frontier"