Because a manufacturer secures a patent for a pharmaceutical compound, the patent does not bar competitors from producing a chemical like it, as long as those chemicals have at least one structural difference with the patented compound.
(A) same as original
(B) That a manufacturer has secured a patent for one of its pharmaceutical compounds do not bar competitors from producing similar chemicals and having at least one important difference from the patented compound
(C) A patent for one of a manufacturer's pharmaceutical compounds does not bar competitors from producing a chemical like the patented compound, as long as the two differ structurally in at least one way
(D) When securing a patent for one of a manufacturer's pharmaceutical compounds, competitors are not barred from the production of chemicals such as the patented compound, provided that there is at least one structural difference
(E) Even if a manufacturer secures a patent for one of its pharmaceutical compounds, this does not bar competitors from the production of a chemical such as the patented compound, but having at least one structural difference from it

OA C

Source: Manhattan Prep