Sentence Correction (SC) | Re: Isotopes in the recently excavated bones of a 14-year-old girl from

As daagh mentions in his post there are some issues in this question.While answering the question the first split that i used was of that.So that keeps B and C.And C has a tense problem so i picked B.Can i know where did i go wrong in this reasoning.It seems to be a tricky question for many ,according to the forum stats.