GMAT Sentence Correction (SC) | Re: stone pieces discovered at the Asforby site

Ancient stone pieces discovered at the Asforby site inEngland, an example of the earliest known tools made in prehistoric Europe, includes flint cores used for weapon creation, blades, flakes and 'debitage' (small chips from tool-working).

A) England, an example of the earliest known tools made in prehistoric Europe,includes
B)England are an example of the earliest known tools made in prehistoric Europe,including
C)England, examples of the earliest known tools made in prehistoric Europe, include