Sentence Correction (SC) | Re: The success of the program to eradicate smallpox has

I imagine many of you were stuck between A and C. Here is a formula I use for SC, RC, and CR when stuck between 2 choices: I ask myself which one of the two choices is undeniably true regardless of the other choice. In this example,

C) something they had not previously considered possible -- better control, if not eradication, of such infections as

sounds perfect to me.

A) on the other hand while it reads kinda right, I am not as confident in saying its as undeniably right as C.

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