GMAT Sentence Correction (SC) | Re: The Leakeys discovered Homo habilis , the first tool user, with two te

I doubt whether E makes any complete sense or for that matter, any of the choices can make the grade.

E. The Leakeys discovered Homo habilis, the first tool user, when two teeth were found -- Can we make out whose two teeth were found? It could be of Homo habilis or for that matter those of the Leakey's or just those of any other animal. Second, 'when' is not the correct diction in the context. It gives an impression that at the very moment of their sighting the two teeth, the discovery