下列极限存在的是__________. A. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/e38cebf6853d2791d272febba724da6d.jpg"/> B. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/79609f9611b1aa29f344da5c287e63d7.jpg"/> C. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/b2d9bc8f6e58548c5a8c8a9d22fdc255.jpg"/> D. <br/> <img src="https://static.zxtiku.com/wangke/imgs/topic/9bdc10943c9765940ce533971109c7c0.jpg"/>