【单选题】
设<img class=jc-formula data-tex=\lim _{ x\rightarrow a }{ \frac { f\left( x \right) -f\left( a \right) }{ { (x-a) }^{ 2 } } } =-1 src=https://huaweicloudobs.ahjxjy.cn/E103C96BFF151DAC29E160A4108E93C6.png style=vertical-align: middle;/>,则在点x=a处( )
① <img class=jc-formula data-tex=f^{ \prime }\left( a \right) src=https://huaweicloudobs.ahjxjy.cn/330C7E4F3259C338D457CB2D57CA14F4.png style=vertical-align: middle;/>存在且不为0
② <img class=jc-formula data-tex=f\left( x \right) src=https://huaweicloudobs.ahjxjy.cn/FB6E53A56CB8DA138AA7D1A4EBCF7519.png style=vertical-align: middle;/>取得极大值
③ <img class=jc-formula data-tex=f\left( x \right) src=https://huaweicloudobs.ahjxjy.cn/FB6E53A56CB8DA138AA7D1A4EBCF7519.png style=vertical-align: middle; width: 52px; height: 26px; width=52 height=26/>取得极小值