Sentence Correction (SC) | Re: Daniel Inouye

A - it modify first term rather than post, can't use comma before that
B - it modify first term rather than post
C - Correctly used comma + ing set up
D - This is not run on sentence and is incorrect because of same reason as in B
E - Creates run on sentence, being is wordy, and verb is missing.

In general, when you are using "that" as a relative pronoun to introduce a modifying clause, you should keep these two things in mind:

1) "that" won't be preceded by a comma
2) "that"
...

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