下列函数在指定区间上单调减少的是（ ）.

<img src、"http://oss.ouchn.cn/ddzx/N601/gongxue/jjsx/img/1-3/image007.png" alt="" align="middle">

<img src、"http://oss.ouchn.cn/ddzx/N601/gongxue/jjsx/img/1-3/image008.png" alt="" align="middle">

<img src、"http://oss.ouchn.cn/ddzx/N601/gongxue/jjsx/img/1-3/image009.png" alt="" align="middle">

<img src、"http://oss.ouchn.cn/ddzx/N601/gongxue/jjsx/img/1-3/image010.png" alt="" align="middle">