GMAT Sentence Correction (SC) | Re: Today’s semi-conductor innovations allow chip makers to design

Today’s semi-conductor innovations allow chip makers to design silicon wafer chips more space efficient now than at any time since their inception.

(A)
silicon wafer chips more space efficient now than at any time since their ---- their ambiguous --X

(B)
silicon wafer chips that are more space efficient than they were at any time since their -- Same as A

(C)
silicon wafer chips that are more space efficient than those at any other time since ---Best choice. That- is used correctly

(D)
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