Meaning SC MGMAT CAT Question

[aashray.thatai]

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)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


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

This question is from one of MGMAT CATs, could you please explain why C is the correct option? I chose D because
I thought "such as" would be better than using "like" in C. Also if you could tell me what else is wrong with D it would be great.
Thanks

[aashray.thatai]

Could someone help me with me this one please?