Which class of mail requires items to be provided with protection against postal inspection?

The correct answer is First Class Mail because this class of mail is designed to handle a variety of important communications and items, including letters, postcards, and small parcels. Unlike other classes, First Class Mail is associated with a higher level of service and often includes options for tracking and delivery confirmation. As a result, items sent via First Class Mail may need to be provided with protection against postal inspection to ensure privacy and security, particularly for sensitive documents or personal information.

Express Mail and Priority Mail, while they do offer expedited services, have different handling protocols and levels of tracking that do not emphasize postal inspection protection as significantly. Standard Mail, primarily used for bulk advertising and marketing materials, typically does not require the same level of protection due to the nature of the items being shipped, which are often less sensitive and not personal in nature. Thus, First Class Mail stands out as requiring such measures, underscoring its focus on secure and timely delivery of important personal and business correspondence.