The sentence that should be revised to show correctly punctuated coordinate adjectives is:
C. Now, the breeze swept through the dry restless grass, whispering as it went.
In this case, "dry" and "restless" are both adjectives that describe the noun "grass." When two or more adjectives equally modify the same noun, they should be separated by a comma. However, "dry" and "restless" are not coordinate adjectives because they cannot be separated by "and" or reversed in order without changing the meaning.
A more appropriately punctuated version of the sentence might read: "Now, the breeze swept through the dry and restless grass, whispering as it went." This maintains clarity while correctly joining the adjectives.
Thus, the best answer choice for revision is option C from your list.