The phrase which must be revised to create parallel structure is, 'To not walk near the quicksand.'
Answer: Option D
<u>Explanation:</u>
Parallel structure is a literary device which is often used by writers and poets to create a smooth flow in writing. In parallel structure, same pattern of words are being used to indicate that all the ideas contains the same level of importance.
In the sentence, ‘The general told Rainsford that he should take a knife, that he should wear moccasins, and to not walk near the quicksand’ if we rephrase the last line after conjunction, then the sentence will become a parallel structure.
‘To not walk near the quicksand’ should be rephrased as ‘that he should not walk near the quicksand.’ So the sentence would be ‘The general told Rainsford that he should take a knife, that he should wear moccasins, and that he should not walk near the quicksand.’