Final answer:
A person must complete four years of honorable service to be eligible to wear one service stripe in the U.S. Navy and Marine Corps, whereas in the U.S. Army, it represents three years of service.
Step-by-step explanation:
To be eligible to wear one service stripe, a person typically must complete four years of honorable service. Service stripes, often called "hash marks,” are worn on the sleeve of the uniform in many military services around the world, and each stripe usually represents a standard period of service which can vary depending on the country's military regulations. For example, in the United States Navy and Marine Corps, each service stripe indicates four years of service, while in the Army it is three years of service. This form of recognition for continued service allows personnel to display their duration of service on their uniform as a mark of their commitment and experience.