Which of these must be avoided in business lettersAPolite wordsBFormal wordsCAbbreviationsDClear detailsAnswer: C. Abbreviations Read Explanation: A business letter is an official dealing with the subjects such as enquiry, order, request, complaint, and apology.Abbreviations must be avoided in business letters Components of a business letterHeadingInside Name & AddressesOpening SalutationSubjectBody of the letterComplementary closeSignatureEnclosuresPost scriptIdentification Mark Read more in App