A and E are out because of unclear pronouns
C is wrong because it changes the meaning; there is no cause relation in C and the subject has been changed from "code" to "tiny isles..."
B and D are left.
B is correct while D is wrong. Ones can see that "because" and "this" together cannot give any sense to the whole sentence.
C is wrong because it changes the meaning; there is no cause relation in C and the subject has been changed from "code" to "tiny isles..."
B and D are left.
B is correct while D is wrong. Ones can see that "because" and "this" together cannot give any sense to the whole sentence.








