GMAT Sentence Correction (SC) | Re: Although reclusive author Harper Lee wrote just one book in

I am still confused about the use of "that" in C because of 2 reasons.
1)"lifetime" is the closest word to "that", isn't it a problem?
2)In MGMAT book, I remember something like "that" should only be used as a connecting word such as the person that wears sunglasses, the book that has a nice cover etc. Here it is used differently. Do I remember wrong or can we make some exceptions to this?

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