against+

against 是介词，选B

against 常常作介词用。
1. 反对;违反（ 与fight /strugle/vote...连用）
The fight against inflation has been going on for almost two years.
抑制通货膨胀的战斗已展开近两年了。
2. 逆;对着
They sounded a sharp warning against all these tendencies.
对于这种种倾向,他们发出了严厉的警告。
3. 倚;靠
His desk is against the wall.
他的办公桌靠墙放着。
4. 以...为背景
The little red house looks so beautiful against the green woods.
那座红色的小屋在翠绿的森林衬托下显得很美。
5. 防备;预防
We bought some warm clothes against the coming winter.
我们添置了一些御寒的衣服以迎接即将来临的冬季。
6. 不利于
She has said nothing against you.
她并没有说任何对你不利的话。