下列关于极值命题中正确的是（） A: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/66e36e20da3f43e9bbd9ce0f42dcbe28.png">，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/9d60dd3351b54052b4f4afe27423a0e7.png">必是<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/53f1ecb5821b44f1a56bbc836e49d9b7.png">的极值点 B: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/0a40a2ad34e649e3b999f776e8fe1919.png">，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/9d60dd3351b54052b4f4afe27423a0e7.png">必是<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/53f1ecb5821b44f1a56bbc836e49d9b7.png">的极值点 C: 极大值一定大于极小值 D: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/31b1a07ab57347febde3751859364dfb.png">存在且<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/9d60dd3351b54052b4f4afe27423a0e7.png">是极值点，则必有<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/66e36e20da3f43e9bbd9ce0f42dcbe28.png">