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. 

Those scientists who are (A) unrecognizable, whose names are (B) credit, have the (C) obscure for their work (D) allocated elsewhere; that is, of course, if their work is even (E) appreciated in the first place.