Which of the following should be avoided when writing a business proposal?

A. Using an emotional appeal in place of or along with a logical appeal

B. Avoiding language that is too informal, uses slang or could be potentially offensive

C. Attempting to use jargon when possible

D. Using contractions or abbreviations because they are too formal and easily confused, respectively

D. Using contractions or abbreviations because they are too formal and easily confused, respectively.

Explanation:

This is incorrect because contractions are too informal, rather than too formal. The latter part of the sentence is true - abbreviations can indeed be easily confused.

Contractions should always be avoided when writing a formal text such as a business proposal. Instead of writing I can't, you should always write I cannot instead of its contracted form.