单选题
2分
![](https://static.yktong.net/courses/batches/1/796/images/c9258866da7014ad1c3142c162dc97ef.jpg)
![](https://static.yktong.net/courses/batches/1/796/images/9590029dc3c0cd7fd3a615a7a610939c.jpg)
![](https://static.yktong.net/courses/batches/1/796/images/5c1173746959f49163c5e2b1cbd0084e.jpg)
![](https://static.yktong.net/courses/batches/1/796/images/c9258866da7014ad1c3142c162dc97ef.jpg)
![](https://static.yktong.net/courses/batches/1/796/images/9590029dc3c0cd7fd3a615a7a610939c.jpg)
![](https://static.yktong.net/courses/batches/1/796/images/5c1173746959f49163c5e2b1cbd0084e.jpg)
参考答案: B