Big Toe Joe, Diane's cat, "hunts" human feet like a tiger stalks gazelle, whenever Diane wiggles her toes, Joe pounces, delivering a "death bite" to her ankle.

A) gazelle, whenever

B) gazelle, for example, whenever

C) gazelle yet whenever

D) No change is necessary,

B) gazelle, for example, whenever

The sentence is grammatically correct, but if you want to add more clarity and specify that the behavior happens specifically when Diane wiggles her toes, option B) would be the best choice. The revised sentence would be:

Big Toe Joe, Diane's cat, "hunts" human feet like a tiger stalks gazelle, for example, whenever Diane wiggles her toes, Joe pounces, delivering a "death bite" to her ankle.

The sentence describes how Big Toe Joe, Diane's cat, hunts human feet similar to how a tiger hunts a gazelle. The word "whenever" indicates that Joe pounces on Diane's feet whenever she wiggles her toes.

Looking at the options:

A) "gazelle, whenever" - This option maintains the correct usage of "whenever" to indicate the timing of Joe's pouncing, so it is correct.

B) "gazelle, for example, whenever" - This option adds the phrase "for example," which is not necessary in this context and does not fit the intended meaning, so it is incorrect.

C) "gazelle yet whenever" - This option changes the word "whenever" to "yet whenever," which alters the meaning of the sentence. The original sentence implies a direct comparison between Joe hunting feet and a tiger hunting a gazelle. Adding "yet" disrupts this comparison, so it is incorrect.

D) "No change is necessary" - This option implies that the original sentence is correct, which it is not. The sentence needs a comma after "gazelle" to separate it from the word "whenever."

Therefore, the correct answer is A) gazelle, whenever.