Which statement accurately describes the regulations for mustaches in uniform?

The statement that mustaches shall not extend below the upper lip line is correct because it aligns with the grooming standards set forth for military uniforms. These regulations aim to maintain a professional appearance and ensure that facial hair, including mustaches, does not interfere with the proper fitting of gas masks or other equipment used in service. The guidelines are implemented to promote uniformity and discipline among personnel while serving in uniform. Maintaining mustaches above the upper lip line helps ensure that all cadets present a polished and consistent appearance, which is an essential aspect of military tradition.