A, B, and E - to end with longer than "were" ....
Left with C and D - were in isolation in C is not a good choice, thus D is correct.
The idiom isolated from is correctly used in this sentence. The comparison is clear and unambiguous.
Left with C and D - were in isolation in C is not a good choice, thus D is correct.
The idiom isolated from is correctly used in this sentence. The comparison is clear and unambiguous.
