关于函数曲线<img src="https://static.zxtiku.com/wangke/imgs/topic/2ab5f661f821083f6e6650f5860908cc.jpg"/>，下列选项正确的是（）<br/> A、函数有极值点<img src="https://static.zxtiku.com/wangke/imgs/topic/78c1496d5be416e92e64e11a26d03262.jpg"/>，曲线无拐点<br/> B、函数无极值点，曲线有拐点<img src="https://static.zxtiku.com/wangke/imgs/topic/06aa75c443c8ced839c123f8409ed53b.jpg"/><br/> C、函数有极值点<img src="https://static.zxtiku.com/wangke/imgs/topic/91a4465e016d9b773ec568eb133c52f8.jpg"/>，曲线有拐点<img src="https://static.zxtiku.com/wangke/imgs/topic/06aa75c443c8ced839c123f8409ed53b.jpg"/><br/> D、函数无极值点，曲线也无拐点