Which type of correspondence carries a formal tone often using company stationery?

The choice of business letters as the correct answer reflects the traditional standards of formal communication within a business context. Business letters are designed to convey professional messages that require a formal tone, and they often utilize company stationery to maintain a standardized, professional appearance.

The use of formal language and a structured format is essential in business letters as they are typically used for important communications such as contracts, legal notices, or official requests. The incorporation of company stationery reinforces the message's authenticity and the entity's professionalism, which is critical in establishing credibility with the recipient.

In contrast, while emails and memos can also be used for formal communication, they often allow for a more casual tone and may not follow the same level of formality as business letters. Reports, meanwhile, serve a different purpose and are usually focused on presenting data or findings rather than facilitating correspondence. Therefore, business letters accurately represent formal correspondence characterized by a specific tone and the use of official company branding.