GMAT Sentence Correction (SC) | Re: Based on records from ancient Athens, each year young

In this sentence non-underlined portion is holding the key hint to right option. I have highlighted the key below. One should try to understand the nature of highlighted portion and then compare it to the nature of parallel that clause in underlined part. Are they parallel ? No. in underlined partthat they used is modifying noun rob, but in non-underlined partthat this robe is presenting a independent idea; it is not modifying rob. Therefore we should look for a answer in which these natures
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