函数<img src="https://static.zxtiku.com/wangke/imgs/topic/2557e4f8598801134b9fdbc20b3a0c96.jpg"/>在点<img src="https://static.zxtiku.com/wangke/imgs/topic/5c0e4f20f2edd26333b0966400743ed5.jpg"/>处取得极大值，则必有（）.<br/> A、<img src="https://static.zxtiku.com/wangke/imgs/topic/89d8f03869711c2cd149fafc51d542b7.jpg"/><br/> B、<img src="https://static.zxtiku.com/wangke/imgs/topic/de9f5350a7b46cc6be6ff517401ad90b.jpg"/><br/> C、<img src="https://static.zxtiku.com/wangke/imgs/topic/921a7736baa43f4b88c7c9e863d716ba.jpg"/>且<img src="https://static.zxtiku.com/wangke/imgs/topic/aef0a3e0a458c57343f62859a6cdd6ab.jpg"/><br/> D、<img src="https://static.zxtiku.com/wangke/imgs/topic/354c1f0112bb998920df39269c2ed977.jpg"/>或<img src="https://static.zxtiku.com/wangke/imgs/topic/1d0c44cfb9998aea4712d3b38b7be85b.jpg"/>不存在