Which of the Following Sentences Avoids the Use of Redundant

Multiple Choice

Which of the following sentences avoids the use of redundant words?

A) The customer returned back the phone stating trivial reasons.
B) We should plan in advance for the future.
C) At the present time, we are conducting two surveys.
D) I am interested in learning more about this procedure.
E) This chapter discusses the basic fundamentals of clear writing.