GMAT Sentence Correction (SC) | Re: A report by the American Academy for the Advancement of

Official Guide 2013 - Sentence Correction - Q#83

27.A report by the American Academy for the Advancement of Science has concluded that much of the currently uncontrolled dioxins to which North Americans are exposed comes from the incineration of wastes.
(A) much of the currently uncontrolled dioxins to which North Americans are exposed comes
(B) much of the currently uncontrolled dioxins that North Americans are exposed to come
(C) much of the dioxins that are currently uncontrolled and that