Answer:
Explanation:
Business letters are a means of formal and official communication between bodies and as such the information disclosed therein must be confidential and kept as such. Only parties who are meant to read it should read it as it may contain sensitive information which is why when Confidentiality is paramount, a business letter is best.
The same goes for situations where a permanent record is required because business letters should have records made available because paper trials are necessary for record keeping and for referral purposes.