In the following question, a sentence is given with certain words in bold. Choose the pair/s of such words which need to be interchanged so as to make the sentence grammatically correct and meaningful.

Planned (A) target has been the (B) obsolescence of so much recent social (C) criticism that the (D) unwary reader might be led to regard is as the primary or even (E) exclusive cause of the trend toward shorter (F) relational duration.