In the sentence, certain words are in bold and numbered from A to E, which are the possible pairs to be interchanged. Choose the pair(s) of words which need to be interchanged to make the sentence grammatically correct and meaningful. 

The (A) monotony and (B) boredom of being (C) conflicts up indoors may heighten personality (D) cooped or heighten communication issues, say mental health (E) experts.