在下列向量中,与向量<img src="/lqwvjeImg/c5/c5a5cd243804fbbcc1e9d25e99958dd3.png"style="width:81px;height:20px;">垂直的单位向量是( )。<br>· <img src="/lqwvjeImg/59/59a2f61de0d5519617b8caa217e96cd1.png"style="width:68px;height:20px;"><br>· <img src="/lqwvjeImg/16/1666998bbd8533afb34fdcf82bf43a34.png"style="width:123px;height:44px;"><br>· <img src="/lqwvjeImg/83/83c2f118cc89a9e5c9eb2956492924dd.png"style="width:48px;height:20px;"><br>· <img src="/lqwvjeImg/39/39afbd9bd7ededacc6a5f081c1f4f2b0.png"style="width:96px;height:44px;">